Researcher Profile and Settings

Affiliation

• Faculty of Engineering　Sustainable Resources Engineering　Geoenvironmental Engineering

Job Title

• Professor

Degree

• Ph.D.（1999/03 Tottori University）
• M.Eng.（1988/03 Tottori University）

URL

https://rml.eng.hokudai.ac.jp/
https://rml.eng.hokudai.ac.jp/home_eng.html

Research funding number

• 00304022

J-Global ID

• 200901051444653746

Research Interests

• microorganism   silica   calcium phosphate compound   calcium carbonate   soft rock   beachrock   ground improvement   engineering geology   test method   new material   property evaluation   mechanical property   non-destructive test   biogrout   preservation material   

Research Areas

• Energy / Earth resource engineering, energy science
• Social infrastructure (civil Engineering, architecture, disaster prevention) / Geotechnical engineering
• Humanities & social sciences / Museology
• Humanities & social sciences / Cultural properties

Educational Organization

•  Bachelor's degree program　School of Engineering
•  Master's degree program　Graduate School of Engineering
•  Doctoral (PhD) degree program　Graduate School of Engineering

Academic & Professional Experience

• 2014/04 - Today Hokkaido University (Division of Sustainable Resources Engineering) Professor
• 2010/04 - 2014/03 Hokkaido University (Division of Sustainable Resources Engineering) Associate Professor
• 2007/04 - 2010/03 Hokkaido University (Division of Field Engineering for Environment) Associate Professor
• 2006/12 - 2007/03 Gifu University (Department of Civil Engineering) Assistant Professor (part-time)
• 2005/04 - 2007/03 Hokkaido University (Division of Field Engineering for Environment) Associate Professor
• 2002/05 - 2005/03 Hokkaido University (Division of Environment and Resources Engineering) Associate Professor
• 2000/02 - 2002/04 Osaka University (Division of Global Architecture) Assistant Professor
• 2001/06 - 2001/09 Gifu University (Department of Civil Engineering) Assistant Professor (part-time)
• 1998/04 - 2000/01 Osaka University (Division of Global Architecture) Research Associate
• 1998/03 - 1998/03 Osaka University (Department of Civil Engineering) Research associate
• 1997/01 - 1998/02 Central Research Institute of Electric Power Industry Chief Researcher
• 1995/08 - 1996/12 Central Research Institute of Electric Power Industry Senior Researcher
• 1990/08 - 1995/07 Central Research Institute of Electric Power Industry Researcher
• 1988/04 - 1990/07 Central Research Institute of Electric Power Industry Assistant Reseacher

Education

• 1997/04 - 1999/03  Tottori University  Graduate School of Engineering  Engineering of Social Development
• 1986/04 - 1988/03  Tottori University  Graduate School of Engineering
• 1982/04 - 1986/03  Tottori University  Faculty of Engineering  Department of Civil Engineering

Association Memberships

• THE SOCIETY FOR BIOTECHNOLOGY, JAPAN   Japan Geoscience Union   Japanese Society for Engineering Education   Japan Society of Engineering Geology   Japan Society of Civil Engineers   The Mining and Materials Orocessing Institute of Japan   Japanese Committee for Rock Mechanics   International Society for Soil Mechanics and Geotechnical Engineering   International Society for Rock Mechanics   The Japanese Geotechnical Society   

Research Activities

Published Papers

• Biosynthesis of a functional silica-based biohybrid material with high Pb(II) capture ability

  Ilham Maulidin, Kazunori Nakashima, Ryo Naota, Anju Pilakka Veedu, Chikara Takano, Satoru Kawasaki

  ACS Sustainable Resource Management 2024/05 [Refereed][Not invited]
  
• Soil erosion control of Urmia Lake using indigenous ureolytic calcifying bacteria

  A. Mohsenzadeh, T. Ebadi, S. M. Fattahi, A. A. Soorki, M. Bolfion, S. Kawasaki

  International Journal of Environmental Science and Technology 2024/02 [Refereed][Not invited]
  
• Biomineralization grouting for beach sand cemented with MICP

  Lutfian Rusdi Daryono, Sonoko Aoki, Masanao Kano, Mimori Miyanaga, Kazunori Nakashima, Satoru Kawasaki

  Journal of the Civil Engineering Forum 10 (1) 31 - 38 2024/01 [Refereed][Not invited]
  
• Combination of cellulose nanofiber and artificial fusion protein for biocementation

  Thiloththama Hiranya Kumari Nawarathna, Jin Sakai, Kazunori Nakashima, Tetsuya Kawabe, Miki Shikama, Chikara Takano, Satoru Kawasaki

  Frontiers in Built Environment 9:1305003 2024/01 [Refereed][Not invited]
  
• Bio-cementation of demolition wastes and recycled aggregates for sustainable production of paving blocks

  H. N. Muhanna, R. K. M. Niras, U. N. C. Prasadini, S. Gowthaman, T. H. K. Nawarathna, M. Chen, S. Kawasaki

  Abstract Book of the 14th International Conference on Sustainable Built Environment – (ICSBE) 2023 36  2023/12 [Refereed][Not invited]
  
• Baseline investigation on enzyme induced calcium phosphate precipitation for solidification of sand

  Sivakumar Gowthaman, Moeka Yamamoto, Meiqi Chen, Kazunori Nakashima, Satoru Kawasaki

  Frontiers in Built Environment 9:1307650 2023/12 [Refereed][Not invited]
  
• State-of-the-art review of soil erosion control by MICP and EICP techniques: Problems, applications, and prospects

  Yong Wang, Xiaohao Sun, Linchang Miao, Hengxing Wang, Linyu Wu, Wenbo Shi, Satoru Kawasaki

  Science of the Total Environment 912 169016  2023/12 [Refereed][Not invited]
  
• The physical and mechanical properties of recycled aggregates strengthened by enzyme induced carbonate precipitation

  Yuru Chen, Angran Tian, Xinyu Luo, Yu Zhou, Qiang Tang, Satoru Kawasaki

  Soils and Foundations 63 (6) 101394  2023/11 [Refereed][Not invited]
  
• Shallow Coastal Carbonate Sediment Mapping for Biomimetics MICP, Case Study of Indonesia Beachrock, Yogyakarta

  Lutfian R. Daryono, Kazunori Nakashima, Satoru Kawasaki

  Extended Abstracts of International Conference on Case Histories in Geotechnical Engineering and 4th AsRTC6 Urban GeoEngineering Symposium (GEOCASE 2023) G1-1 - G1-4 2023/09 [Refereed][Not invited]
  
• Eco-friendly soil stabilization method using fish bone as cement material

  Maksym Avramenko, Kazunori Nakashima, Chikara Takano, Satoru Kawasaki

  Science of the Total Environment 900 165823  2023/07 [Refereed][Not invited]
  
• Characterizing microbial and CO2-induced carbonate minerals: Implications for soil stabilization in sandy environments

  Hamed Abdeh Keykha, Alireza Zangani, Hadi Mohamadzadeh Romiani, Afshin Asadi, Satoru Kawasaki, Niloofar Radmanesh

  Minerals 13 (7) 976  2023/07 [Refereed][Not invited]
  
• Isolation of acid tolerant bacteria capable of metal adsorption from acid mine drainage without neutralization

  S. Iwama, C. Takano, K. Nakashima, H. Aoyagi, S. Kawasaki

  Proceedings of the 6th IWA International Conference on eco-Technologies for Wastewater Treatment: ecoSTP2023 2023/06 [Refereed][Not invited]
  
• Metal biosorption from wastewater under acidic environment

  C. Takano, K. Nakashima, S. Kawasaki, H. Aoyagi

  Proceedings of the 6th IWA International Conference on eco-Technologies for Wastewater Treatment: ecoSTP2023 2023/06 [Refereed][Not invited]
  
• Effects of humic acid on process of microbial induced carbonate precipitation

  M. Chen, S. Gowthaman, K. Nakashima, C. Takano, S. Kawasaki

  Proceedings of the 9th International Congress on Environmental Geotechnics 5 31 - 38 2023/06 [Refereed][Not invited]
  
• Baseline investigation on soil solidification through biocementation using airborne bacteria

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Chikara Takano, Satoru Kawasaki

  Frontiers in Bioengineering and Biotechnology 11:1216171 2023/06 [Refereed][Not invited]
  
• Functional modification of mussel adhesive protein to control solubility and adhesion property

  Anju Pilakka Veedu, Kazunori Nakashima, Hayahide Shiga, Takahiro Sato, Kasun Godigamuwa, Naoki Hiroyoshi, Satoru Kawasaki

  Journal of Bioscience and Bioengineering 1 - 7 2023/05 [Refereed][Not invited]
  
• Field experimentation of bio-cementation using low-cost cementation media for preservation of slope surface

  Sivakumar Gowthaman, Hiromu Koizumi, Kazunori Nakashima, Satoru Kawasaki

  Case Studies in Construction Materials 18 e02086  2023/04 [Refereed][Not invited]
  
• Interfacial biosilica coating of chitosan gel using fusion silicatein to fabricate robust hybrid material for biomolecular applications

  Kasun Godigamuwa, Kazunori Nakashima, Sota Tsujitani, Ryo Naota, Ilham Maulidin, Satoru Kawasaki

  Journal of Materials Chemistry B 11 1654 - 1658 2023/02 [Refereed][Not invited]
  
• Soil improvement using calcium phosphate compounds as a novel sustainable method: A review

  Maksym Avramenko, Kazunori Nakashima, Chikara Takano, Satoru Kawasaki

  International Journal of GEOMATE 24 (101) 68 - 75 2023/01 [Refereed][Not invited]
  
• Naturally derived cements learned from the wisdom of ancestors: A literature review based on the experiences of ancient China, India and Rome

  Zhan Su, Zhen Yan, Kazunori Nakashima, Chikara Takano, Satoru Kawasaki

  Materials 16 (2) 603  2023/01 [Refereed][Not invited]
   

  For over a thousand years, many ancient cements have remained durable despite long-term exposure to atmospheric or humid agents. This review paper summarizes technologies of worldwide ancient architectures which have shown remarkable durability that has preserved them over thousands of years of constant erosion. We aim to identify the influence of organic and inorganic additions in altering cement properties and take these lost and forgotten technologies to the production frontline. The types of additions were usually decided based on the local environment and purpose of the structure. The ancient Romans built magnificent structures by making hydraulic cement using volcanic ash. The ancient Chinese introduced sticky rice and other local materials to improve the properties of pure lime cement. A variety of organic and inorganic additions used in traditional lime cement not only changes its properties but also improves its durability for centuries. The benefits they bring to cement may also be useful in enzyme-induced carbonate precipitation (EICP) and microbially induced carbonate precipitation (MICP) fields. For instance, sticky rice has been confirmed to play a crucial role in regulating calcite crystal growth and providing interior hydrophobic conditions, which contribute to improving the strength and durability of EICP- and MICP-treated samples in a sustainable way.
• Densification of sandy soil using geopolymer-modified microbial induced carbonate precipitation

  H. M. R. A. Bandara, B. W. C. E. Bandara, T. H. K. Nawarathna, S. Gowthaman, K. Nakashima, S. Kawasaki

  Proceedings of the 13th International Conference on Sustainable Built Environment - 2022 (ICSBE 2022) 2022/12 [Refereed][Not invited]
  
• Metal biosorption process under strongly acidic condition

  Chikara Takano, Kazunori Nakashima, Satoru Kawasaki, Hideki Aoyagi

  Proceedings of the 27th Symposium of Young Asian Biological Engineers’ Community (YABEC2022) 2022/12 [Refereed][Not invited]
  
• Prospects and merits of using calcium phosphate compounds for soil improvement: A review

  Maksym Avramenko, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Twelveth International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2022) 90 - 95 2022/11 [Refereed][Not invited]
  
• Naturally derived cements for construction and building materials learned from the wisdom of ancestors: A literature review

  Su Zhan, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Twelveth International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2022) 114 - 118 2022/11 [Refereed][Not invited]
  
• Biomineralization Grouting for Beach Sand Cemented with MICP

  Lutfian Rusdi Daryono, Sonoko Aoki, Masanao Kano, Mimori Miyanaga, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the 2022 Annual National Conference 26th PIT HATTI (The 26th Indonesian Society for Geotechnical Engineering (ISGE) Annual Conference) 2022/11 [Refereed][Not invited]
  
• Feasibility of bacterial-enzyme induced carbonate precipitation technology for stabilizing fine-grained slope soils

  Sivakumar Gowthaman, Takashi Iki, Aoi Ichinohe, Kazunori Nakashima, Satoru Kawasaki

  Frontiers in Built Environment 8:1044598 1 - 15 2022/10/12 [Refereed][Not invited]
   

  Microbial Induced Carbonate Precipitation (MICP) has recently become a new technology for stabilizing the slope surface. The applicability of MICP, however, is limited in fine-grained soils due to the restrictions regarding the transportation of bacteria cells. The purpose of this study was to assess the feasibility of an alternative called Bacterial-Enzyme Induced Carbonate Precipitation (B-EICP) for stabilizing the fine-grained slope soils. Unlike the MICP strategy (involving whole-cells of bacteria), the proposed B-EICP utilizes bacterial urease to induce the bio-cement formation within soil. The whole-cell culture of Lysinibacillus xylanilyticus was subjected to cyclic sonication to extract the free urease suspension. The B-EICP treatment was performed to the columns prepared using two different soils obtained from representative expressway slopes. The cementation responses of the proposed B-EICP were compared with that of typical MICP method, especially from the following viewpoints, (i) adaptability to soil with high fine-grained content, (ii) conditions under which B-EICP can be effectively applied and (iii) cementation under low temperature. The results revealed that the extract solution had higher urease activity compared to original bacteria culture, and the activity remained more stable at low temperature conditions (15°C). The results further confirmed that B-EICP method is more suitable for stabilizing soils with large amount of fine particles. Comparing with MICP, the B-EICP resulted higher unconfined compressive strength (over 1200 kPa) and deeper cementation in the silty sand. Microscale analysis suggested that the B-EICP could induce smaller calcium carbonate crystals than that by MICP, but the number of crystals in B-EICP were significantly more, thus contributed to increased particle-particle cementation.
• State-of-the-art review on engineering uses of calcium phosphate compounds: An eco-friendly approach for soil improvement

  Maksym Avramenko, Kazunori Nakashima, Satoru Kawasaki

  Materials 15 (19) 6878 - 6878 2022/10/03 [Refereed][Not invited]
   

  Greenhouse gas emissions are a critical problem nowadays. The cement manufacturing sector alone accounts for 8% of all human-generated emissions, and as the world’s population grows and globalization intensifies, this sector will require significantly more resources. In order to fulfill the need of geomaterials for construction and to reduce carbon dioxide emissions into the atmosphere, conventional approaches to soil reinforcement need to be reconsidered. Calcium phosphate compounds (CPCs) are new materials that have only recently found their place in the soil reinforcement field. Its eco-friendly, non-toxic, reaction pathway is highly dependent on the pH of the medium and the concentration of components inside the solution. CPCs has advantages over the two most common environmental methods of soil reinforcement, microbial-induced carbonate precipitation (MICP) and enzyme induced carbonate precipitation (EICP); with CPCs, the ammonium problem can be neutralized and thus allowed to be applied in the field. In this review paper, the advantages and disadvantages of the engineering uses of CPCs for soil improvement have been discussed. Additionally, the process of how CPCs perform has been studied and an analysis of existing studies related to soil reinforcement by CPC implementation was conducted.
• Metal biosorption process under low pH conditions for E-waste recycling and polluted water treatment

  Chikara Takano, Kazunori Nakashima, Satoru Kawasaki, Hideki Aoyagi

  Proceedings of the 15th Asian Congress on Biotechnology 2022/10 [Refereed][Not invited]
  
• Influence of humic acid on microbial induced carbonate precipitation for organic soil improvement

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Environmental Science and Pollution Research 1 - 11 0944-1344 2022/09 [Refereed][Not invited]
  
• Control of adhesion property of mussel foot protein by fusing soluble protein

  Anju Pilakka Veedu, Kazunori Nakashima, Takahiro Sato, Satoru Kawasaki

  The 19th Asian Pacific Confederation of Chemical Engineering (APCChE) Congress 2022/08 [Refereed][Not invited]
  
• Metal biosorption process under strongly acidic conditions: A part of sustainable metal recycling system

  Chikara Takano, Koichi Murayama, Kazunori Nakashima, Satoru Kawasaki, Hideki Aoyagi

  International Union of Microbiological Societies 2022/07 [Refereed][Not invited]
  
• Polymer‑assisted enzyme induced carbonate precipitation for non‑ammonia emission soil stabilization

  Zhen Yan, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Scientific Reports 12 (1) 8821  2022/05/25 [Refereed][Not invited]
   

  Abstract Biocementation using enzyme induced carbonate precipitation (EICP) process has become an innovative method for soil improvement. One of the major limitations in scaling-up of biocement treatment is the emission of gaseous ammonia during the urea hydrolysis, which is environmentally hazardous. In order to eliminate this shortcoming, this paper presents a series of experiments performed to evaluate a novel approach for preventing the ammonia byproducts in the EICP process via the use of polyacrylic acid (PAA). Through the adjustment of the pH to acidic, PAA not only promotes the enzyme activity, but also averts the conversion of ammonium to gaseous ammonia and its release, thus preventing any harm to the environment. The sand samples were treated with cementation solution and assessed for improvement in strength. Calcium carbonate content measurements and X-ray powder diffraction analysis identified the calcite crystals precipitated in the soil pores. Scanning electron microscopy analysis clearly showed that calcium carbonate was precipitated connecting soil particles, thus providing a uniaxial compressive strength (UCS) of up to 1.65 MPa. Overall, the inhibition in the speciation of gaseous ammonia shows the great potential of PAA for large-scale promotion of biocement.
• Functional modification of mussel adhesive protein for the control of adhesion and aggregation property

  Anju Pilakka Veedu, Kazunori Nakashima, Takahiro Sato, Satoru Kawasaki

  European Federation of Biotechnology (EFB) Spring 2022 2022/05 [Refereed][Not invited]
  
• Effects of reaction conditions on EICP-treated desert aeolian sand

  Linyu Wu, Linchang Miao, Satoru Kawasaki, Hengxing Wang

  KSCE Journal of Civil Engineering 2022/03/24 [Refereed][Not invited]
  
• Durability improvement of biocemented sand by fiber-reinforced MICP for coastal erosion protection

  Md Al Imran, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  Materials 15 (7) 2389 - 2389 2022/03/24 [Refereed][Not invited]
   

  Soil improvement via MICP (microbially induced carbonate precipitation) technologies has recently received widespread attention in the geoenvironmental and geotechnical fields. The durability of MICP-treated samples remains a critical concern in this novel method. In this work, fiber (jute)-reinforced MICP-treated samples were investigated to evaluate their durability under exposure to distilled water (DW) and artificial seawater (ASW), so as to advance the understanding of long-term performance mimicking real field conditions, along with improvement of the MICP-treated samples for use in coastal erosion protection. Primarily, the results showed that the addition of fiber (jute) improved the durability of the MICP-treated samples by more than 50%. Results also showed that the wet–dry (WD) cyclic process resulted in adverse effects on the mechanical and physical characteristics of fiber-reinforced MICP-treated samples in both DW and ASW. The breakdown of calcium carbonates and bonding effects in between the sand particles was discovered to be involved in the deterioration of MICP samples caused by WD cycles, and this occurs in two stages. The findings of this study would be extremely beneficial to extend the insight and understanding of improvement and durability responses for significant and effective MICP treatments and/or re-treatments.
• Solubilization and aggregation control of silica-polymerizing enzyme fused with a removable soluble protein

  Hidetoshi Oguri, Kazunori Nakashima, Kasun Godigamuwa, Junnosuke Okamoto, Yudai Takeda, Fumiyoshi Okazaki, Masafumi Sakono, Satoru Kawasaki

  Journal of Bioscience and Bioengineering 133 (3) 222 - 228 1389-1723 2022/03 [Refereed][Not invited]
  
• Developing a new soil improvement technology using calcium phosphate bio-cement derived from bone waste

  M. M, S. Ahamed, M. Y. M. Husny, Sivakumar Gowthaman, Satoru Kawasaki

  The 3rd Edition of Advancements in Geotechnical Engineering from Research to Practice (AGERP): International Workshop on Biogeotechnics 2022/02 [Refereed][Not invited]
  
• Coir fiber reinforced EICP-based bio-cementation for the production of low-cost sand bricks

  R. Dinoth, P. Purushalini, S. Gowthaman, Satoru Kawasaki

  The 3rd Edition of Advancements in Geotechnical Engineering from Research to Practice (AGERP): International Workshop on Biogeotechnics 2022/02 [Refereed][Not invited]
  
• Bio-cementation of demolition waste and recycled aggregates for sustainable pavement construction

  W. M. Nabris, J. P. Roshan, S. Gowthaman, Satoru Kawasaki

  The 3rd Edition of Advancements in Geotechnical Engineering from Research to Practice (AGERP): International Workshop on Biogeotechnics 2022/02 [Refereed][Not invited]
  
• Removal of ammonium by-products from the effluent of bio-cementation system through struvite precipitation

  Sivakumar Gowthaman, Arash Mohsenzadeh, Kazunori Nakashima, Satoru Kawasaki

  Materials Today: Proceedings 61 (2) 243 - 249 2214-7853 2022/02 [Refereed][Not invited]
  
• Bio‐mediated soil improvement: An introspection into processes, materials, characterization and applications

  Ning‐Jun Jiang, Yi‐Jie Wang, Jian Chu, Satoru Kawasaki, Chao‐Sheng Tang, Liang Cheng, Yan‐Jun Du, Bettadapura S. Shashank, Devendra N. Singh, Xiao‐Le Han, Yu‐Ze Wang

  Soil Use and Management 38 (1) 68 - 93 0266-0032 2022/01/28 [Refereed][Not invited]
  
• Beachrock formation mechanism using multiproxy experimental data from natural and artificial beachrocks: Insights for a potential soft engineering method

  Giannis Saitis, Anna Karkani, Eleni Koutsopoulou, Konstantinos Tsanakas, Satoru Kawasaki, Niki Evelpidou

  Journal of Marine Science and Engineering 10 (1) 87  2022/01/10 [Refereed][Not invited]
  
• Geochemical characterization of the coastal alluvial aquifer in Wates, Yogyakarta, Indonesia

  Phyu Phyu Thin, Heru Hendrayana, Wahyu Wilopo, Satoru Kawasaki

  Proceedings of the 13th AUN/SEED-Net Regional Conference on Geological and Geo-Resource Engineering (RC GeoE 2021) 2021/12 [Refereed][Not invited]
  
• Influence of cementation level on the mechanical behavior of bio-cemented slope soil treated by surface injection

  S. Gowthaman, M. Chen, H. Nakamura, K. Nakashima, S. Kawasaki

  Proceedings of the Third International Conference on Geotechnical Engineering ICGE-Colombo-2020 401 - 406 2021/12 [Refereed][Not invited]
  
• Polymer modified microbial induced carbonate precipitation: Novel approach to densify the loose sand

  T. H. K. Nawarathna, K. Nakashima, S. Kawasaki

  Proceedings of the Third International Conference on Geotechnical Engineering ICGE-Colombo-2020 332 - 336 2021/12 [Refereed][Not invited]
  
• A soil improvement method based on plant-derived urease-induced carbonate precipitation

  R. A. N. Dilrukshi, K. Nakashima, S. Kawasaki

  Proceedings of the Third International Conference on Geotechnical Engineering ICGE-Colombo-2020 361 - 366 2021/12 [Refereed][Not invited]
  
• Aggregation of magnetite particles by mussel adhesive protein triggered by protease

  Anju Pilakka Veedu, Kazunori Nakashima, Hiroki Miyagawa, Satoru Kawasaki

  The 26th Symposium of Young Asian Biological Engineers’ Community (YABEC2021) 2021/11 [Refereed][Not invited]
  
• Plant enzyme induced carbonate precipitation for sand cementation

  Linyu Wu, Linchang Miao, Satoru Kawasaki

  Proceedings of the Eleventh International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2021) 63 - 68 2021/11 [Refereed][Not invited]
  
• High water content peat soil improved by MICP technique with fiber reinforcement

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Shin Komatsu, Satoru Kawasaki

  Proceedings of the Eleventh International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2021) 16 - 21 2021/11 [Refereed][Not invited]
  
• Evaluating the effects of polymers on microbially induced carbonate precipitation

  Zhen Yan, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Eleventh International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2021) 10 - 15 2021/11 [Refereed][Not invited]
  
• Used Paper Fibers for Sustainably Enhancing the MICP Stabilization of Sand

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Shin Komatsu, Satoru Kawasaki

  Proceedings of the 6th GeoChina International Conference on Civil & Transportation Infrastructures: From Engineering to Smart & Green Life Cycle Solutions (GeoChina 2021) 52 - 64 2021/09/19 [Refereed][Not invited]
  
• Experimental study on sand stabilization using bio-cementation with wastepaper fiber integration

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Shin Komatsu, Satoru Kawasaki

  Materials 14 (18) 5164  2021/09/08 [Refereed][Not invited]
   

  Recently, green materials and technologies have received considerable attention in geotechnical engineering. One of such techniques is microbially-induced carbonate precipitation (MICP). In the MICP process, CaCO3 is achieved bio-chemically within the soil, thus enhancing the strength and stiffness. The purpose of this study is to introduce the wastepaper fiber (WPF) onto the MICP (i) to study the mechanical properties of MICP-treated sand with varying WPF content (0-8%) and (ii) to assess the freeze-thaw (FT) durability of the treated samples. Findings revealed that the ductility of the treated samples increases with the increase in WPF addition, while the highest UCS is found with a small fiber addition. The results of CaCO3 content suggest that the WPF addition enhances the immobilization of the bacteria cells, thus yielding the precipitation content. However, shear wave velocity analysis indicates that a higher addition of WPF results in rapid deterioration of the samples when subjected to freeze-thaw cycles. Microscale analysis illuminates that fiber clusters replace the solid bonding at particle contacts, leading to reduced resistance to freeze-thaw damage. Overall, the study demonstrates that as a waste material, WPF could be sustainably reused in the bio-cementation.
• Calcium phosphate biocement using bone meal and acid urease: An eco-friendly approach for soil improvement

  Sivakumar Gowthaman, Moeka Yamamoto, Kazunori Nakashima, Volodymyr Ivanov, Satoru Kawasaki

  Journal of Cleaner Production 319 128782  2021/08/22 [Refereed][Not invited]
  
• Artificial fusion protein to facilitate calcium carbonate mineralization on insoluble polysaccharide for efficient biocementation

  Thiloththama H. K. Nawarathna, Kazunori Nakashima, Tetsuya Kawabe, Wilson Mwandira, Kiyofumi Kurumisawa, Satoru Kawasaki

  ACS Sustainable Chemistry & Engineering 9 (34) 11493 - 11502 2168-0485 2021/08/12 [Refereed][Not invited]
   

  Biomineralization is a process of mineral formation in living organisms. Compared with nonbiogenic minerals, biominerals can be defined as organic-inorganic hybrid materials that have excellent physical and optical properties. In the current study, an artificial protein mimicking the outer shell of crayfish, composed of CaCO3, chitin, and proteins, was developed to facilitate organic-inorganic hybrid material formation by precipitation of calcium carbonate on the chitin matrix. The fusion protein (CaBP-ChBD) was constructed by introducing a short-sequence calcite-binding peptide (CaBP) into the chitin-binding domain (ChBD). Calcium carbonate precipitation experiments by enzymatic urea hydrolysis revealed that a significant increase in the CaCO3 formation was achieved by adding CaBP-ChBD. Also, CaCO3 was efficiently deposited on chitin particles decorated with CaBP-ChBD. Most interestingly, CaBP-ChBD would improve the performance in sand solidification more efficiently and sustainably in the process of biocementation technique. The developed recombinant protein could be used for the sustainable production of organic-inorganic green materials for engineering applications.
• CO2-induced carbonate minerals as soil stabilizing agents for dust suppression

  Hamed A. Keykha, Hadi Mohamadzadeh Romiani, Ehsan Zebardast, Afshin Asadi, Satoru Kawasaki

  Aeolian Research 52, 100731 2021/08/03 [Refereed][Not invited]
  
• Effect of scallop powder addition on MICP treatment of amorphous peat

  Sivakumar Gowthaman, Meiqi Chen, Kazunori Nakashima, Satoru Kawasaki

  Frontiers in Environmental Science 9: 690376 1 - 13 2021/07/12 [Refereed][Not invited]
   

  Peat is one of the most challenging and problematic soils in the fields of geotechnical and environmental engineering. The most critical problems related to peat soils are extremely low strength and high compressibility, resulting in poor inhabitancy and infrastructural developments in their vicinity. Thus far, peat soils were stabilized using Portland cement; however, the production of Portland cement causes significant emission of greenhouse gases, which is not environmentally desirable. Microbial-induced carbonate precipitation (MICP) is an innovative technique for improving the mechanical properties of soil through potentially environmentally friendly processes. This article presents a laboratory study carried out with the aim of investigating the viability and effect of scallop shell powder (SSP) on enhancing the mechanical properties of the MICP-treated amorphous peat. The hypothesis was that the distribution of SSP (as-derived calcite particles) would (i) provide more nucleation sites to precipitates and (ii) increase the connectivity of MICP bridges to facilitate mineral skeleton to amorphous peat, accompanied by an increase in its compressive strength. Specimens were treated at varying combinations of SSP and MICP reagents, and the improvement was comprehensively assessed through a series of unconfined compression tests and supported by microscale and chemical analyses such as scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction analysis. The outcomes showed that incorporating SSP in MICP treatment would be a promising approach to treat amorphous peat soils. The proposed approach could improve the unconfined compressive strength by over 200% after a 7-day curing period, while the conventional MICP could not exhibit any significant improvements.
• Durability analysis of bio‑cemented slope soil under the exposure of acid rain

  Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Journal of Soils and Sediments 21 2831 - 2844 2021/06/11 [Refereed][Not invited]
  
• Distribution and cementation characteristics of beachrocks along southern, southwestern and western coast of Sri Lanka

  Pahala Ge Nishadi Nayanthara, Anjula Buddhika Nayomi Dassanayake, Kazunori Nakashima, Satoru Kawasaki

  Journal of Sedimentary Environments 6 93 - 106 2662-5571 2021/06 [Refereed][Not invited]
   

  Beachrocks are sedimentary structures where gravelly or sandy beaches have been transformed into rock outcrops formed through precipitation of connective cements amid their interstices. They are well-noted coastal features along the coastal belt of Sri Lanka due to the prevalent tropical climate. This study was aimed at gathering data on surface nature and cementation characteristics of beachrock occurrences along a part of Sri Lankan shoreline through field observations and a series of analyses including X-ray diffraction, X-ray fluorescence, scanning electron microscopy (SEM) techniques and petrographic thin-section analysis. The combined research findings from different techniques are also employed as a preliminary step to determine the formation mechanism of the studied beachrocks. The seaward-inclined low-angle beds running parallel to present shoreline are composed mostly of sandstone with occasional conglomerate. Almost all the beachrocks are made of quartz grains amalgamated by cement. One remarkable feature of Sri Lankan beachrocks is the presence of heavy minerals generally in thin lamina form. The cementing agents are predominantly composed of metastable carbonate phases, high magnesium calcite (HMC) and aragonite (Ar) with varying microfabrics and textures. From SEM examinations and thin-section images, main morphologies identified are acicular Ar, scalenohedral magnesium calcites along with bridge cements and micritic coatings which are typical of a marine-phreatic precipitation with the exception of occasional meniscus cements. Further, the presence of evidences of living organisms may be an indication of influence from the biological aspects which can be confirmed by more detailed analyses.
• Fabrication of silica on chitin in ambient conditions using silicatein fused with a chitin-binding domain

  Kasun Godigamuwa, Kazunori Nakashima, Sota Tsujitani, Satoru Kawasaki

  Bioprocess and Biosystems Engineering 44 (9) 1883 - 1890 2021/05/11 [Refereed][Not invited]
  
• Bio-mediated soil improvement using plant derived enzyme in addition to magnesium ion

  Md Al Imran, Kazunori Nakashima, Satoru Kawasaki

  Crystals 11 (5) 516  2073-4352 2021/05/06 [Refereed][Not invited]
   

  Recently, soil improvement using EICP (Enzyme-Induced Carbonate Precipitation) methods in the geotechnical and geo-environmental field has become a prominent interest worldwide. The objective of this study was to develop an improved extraction technique of crude urease from watermelon seeds in both dry and germinated conditions. Subsequently, this study also analyzed the improvement methodology of crystal polymorphs and soil bonding incorporation of various Mg2+/Ca2+ ratios. The optimization of enzyme-mediated carbonate precipitation was also investigated by Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) analysis. Results confirmed that the precipitated crystals are mainly calcite, vaterite and aragonite primarily (depending on the Mg2+/Ca2+ ratios). Therefore, to improve the bonding capacity in between the sand particles a novel improvement methodology was investigated by adding various Mg2+/Ca2+ ratios. The mechanical properties of the treated soil (Mikawa Sand, D-50 = 0.870 mm) specimens were tested by unconfined compressive strength (UCS) and this confirmed the effectiveness of adding various Mg2+/Ca2+ ratios. The results of the UCS tests showed that, the lower molar ratios of Mg2+/Ca2+ can significantly improve the UCS of the specimen (up to 50%) which could be considered a significant outcome for different bio-geotechnical applications.
• Fabrication of chitosan gel-silica hybrid materials using fusion silicatein

  Kasun Godigamuwa, Kazunori Nakashima, Satoru Kawasaki

  Virtual conference organized by the European Federation of Biotechnology (EFB2021) 2021/05 [Refereed][Not invited]
  
• Insights in beachrock formation mechanism using multiproxy experimental data: Case study of Diolkos, Corinth, Greece

  Giannis Saitis, Konstantinos Tsanakas, Anna Karkani, Satoru Kawasaki, Niki Evelpidou

  European Geosciences Union General Assembly 2021, vEGU21 2021/04/27 [Refereed][Not invited]
  
• Effect of wetting and drying cycles on the durability of bio‑cemented soil of expressway slope

  S. Gowthaman, K. Nakashima, S. Kawasaki

  International Journal of Environmental Science and Technology Online first article 1 - 14 2021/04/15 [Refereed][Not invited]
  
• Experimental study on strengthening near-surface of slopes using bio-grouting technique

  Sivakumar Gowthaman, Kazunori Nakashima, Hiromi Nakamura, Satoru Kawasaki

  Proceedings of the 1st International Symposium on Construction Resources for Environmentally Sustainable Technologies (CREST 2020) 2021/03/10 [Refereed][Not invited]
  
• Green soil improvement: using carbon dioxide to enhance the behaviour of clay

  Hadi Mohamadzadeh Romiani, Hamed Abdeh Keykha, Milad Talebi, Afshin Asadi, Satoru Kawasaki

  Proceedings of the Institution of Civil Engineers - Ground Improvement Ahead of Print 1 - 26 1755-0750 2021/02/22 [Refereed][Not invited]
  
• Improvement of using crude extract urease from watermelon seeds for biocementation technology

  Md Al Imran, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  International Journal of GEOMATE 20 (78) 148 - 153 2186-2982 2021/02 [Refereed][Not invited]
   

  In recent years, the formation of artificial beachrock and bio-cementation method has gained considerable attention as a sustainable alternative tool in the area of geotechnical and geo-environmental engineering field for soil improvement and construction materials. In general, earlier methods of soil improvement were mostly concentrated on microbes (Bacteria, Fungi, etc.) as a source of urease enzyme widely known as MICP method (Microbial Induced Carbonate Precipitation). To address some of the key limitations of MICP method this study focused on using crude enzyme (low cost, eco-friendly). Crude enzyme was extracted from watermelon seeds (Citrullus lanatus) considered as "food waste material" and the carbonate formation process known as EICP "Enzyme Induced Carbonate Precipitation." Crushed and blended watermelon seeds (both dry and germinated) used as a source of urease enzyme. Subsequently, their urease activity was also investigated with various environmental parameters (Temperature, pH, etc.) and investigated the carbonate precipitation trend using calcium chloride (CaCl2) and urea [(CO(NH2)(2)]. The form of carbonate (calcite, aragonite, vaterite, etc.) was also confirmed by XRD and SEM-EDX analysis. Finally, syringe (d = 2.3 cm, h= 7.1 cm) sand solidification test was conducted using commercially available "Mikawa sand" (mean diameter, D-50 = 870 mm) and successfully achieved unconfined compressive strength (UCS) of about 1.2 MPa at neutral pH (similar to 7) and temperature condition (30 degrees C) considering various curing days and conditions. This study could be useful as an eco-friendly and sustainable method for numerous bio-geotechnical applications (for instance, ground improvement, liquefaction mitigation, artificial beach rock formations, coastal erosion protection, etc.) and the extracted crude urease from watermelon seeds could play as an alternative to replace commercially available urease for carbonate precipitation.
• Evaluating mechanical strength of peat soil treated by fiber incorporated bio-cementation

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  International Journal of GEOMATE 20 (78) 121 - 127 2186-2982 2021/02 [Refereed][Not invited]
   

  Peat soil is an accumulation of partially decayed vegetation, formed under the condition of nearly permanent water saturation, which makes the high moisture and compressibility as two main features of peat. In recent years, the lack of construction lands diverts researchers' attention to make use of marginal grounds, like peatland, after some improvements. The past decade has witnessed a growing interest in microbial induced carbonate precipitation (MICP) due to its reliability, broad application, and potential contribution to sustainable and green development. This study has two primary aims: (i) investigating the feasibility and effectiveness of MICP in peat soil combined with bamboo fiber reinforcement, and (ii) ascertaining the mechanism of bamboo fiber incorporated MICP. Bamboo fiber possesses some unparalleled advantages owing to its fast growth and ability to survive in diverse climates. This study differs from previous researches in the use of native bacteria isolated from the peat soil, while most of them were conducted using exogenous bacteria, which might pose a threat regarding adaption and microbial pollution. Different concentrations of cementation resources (1-3 mol/L) and proportion of fibers (0-50%) were studied, and each case was well designed. Treated samples were subjected to the fall cone test to estimate the undrained shear strength at certain time intervals. The results revealed that samples with higher fiber content gained higher strength than others did, whereas high initial cementation resources in soil could reduce strength. Microscale observations were also performed on treated samples to clarify the mechanism of MICP incorporated with fiber.
• A two-stage treatment process for the management of produced ammonium by-products in ureolytic bio-cementation process

  A. Mohsenzadeh, E. Aflaki, S. Gowthaman, K. Nakashima, S. Kawasaki, T. Ebadi

  International Journal of Environmental Science and Technology Online first article 1735-1472 2021/01/27 [Refereed][Not invited]
  
• Shoreline mapping based on beachrocks identification in Krakal-Sadranan beach, Yogyakarta, Indonesia

  Lutfian R. Daryono, Kazunori Nakashima, Satoru Kawasaki, Anastasia D. Titisari, Didit H. Barianto, Imam Suyanto, Arief Rahmadi

  Bulletin of Engineering Geology and the Environment 80 (3) 2825 - 2844 1435-9529 2021/01/10 [Refereed][Not invited]
   

  A great deal of progress has been made in recent years to investigate the chemical characteristics of beachrocks. Beachrocks found in Krakal-Sadranan Beach (Yogyakarta, Indonesia) are spread locally, parallel to the coastline with a breadth of about 10-30 m(2). In this research, unmanned aerial vehicle (UAV) drone mapping, geological analysis, direct current resistivity survey, and surface seismic surveys were conducted to detect the underground structure of the beachrocks and to emphasize the coastal mapping based on targeted beachrocks. The correlation was developed between the sections and the data on the study site. Toward survey validation, laboratory tests were conducted on the beachrock samples collected from the study site to identify its properties. The evolution of the coastal zone based on beachrocks study is highly affected by relative sea-level changes that were described in the 3D model of beachrocks. The coastal changes are significantly impact the natural and cultural resources, and the understanding of coastal evolution is important for the preservation, development, and management of the coastal zone. This paper focused on the cementation processes and mechanism of beachrocks as a natural wave barrier in a tropical area, which is also appropriate for advanced marine ecosystems study including shorelines microbiotas.
• Biosorption of Pb (II) and Zn (II) from aqueous solution by Oceanobacillus profundus isolated from an abandoned mine

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Allison Arabelo, Kawawa Banda, Imasiku Nyambe, Meki Chirwa, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka

  Scientific Reports 10 (1) 21189 - 21189 2020/12 [Refereed][Not invited]
   

  The present study investigated biosorption of Pb (II) and Zn (II) using a heavy metal tolerant bacterium Oceanobacillus profundus KBZ 3-2 isolated from a contaminated site. The effects of process parameters such as effect on bacterial growth, pH and initial lead ion concentration were studied. The results showed that the maximum removal percentage for Pb (II) was 97% at an initial concentration of 50 mg/L whereas maximum removal percentage for Zn (II) was at 54% at an initial concentration of 2 mg/L obtained at pH 6 and 30 °C. The isolated bacteria were found to sequester both Pb (II) and Zn (II) in the extracellular polymeric substance (EPS). The EPS facilitates ion exchange and metal chelation-complexation by virtue of the existence of ionizable functional groups such as carboxyl, sulfate, and phosphate present in the protein and polysaccharides. Therefore, the use of indigenous bacteria in the remediation of contaminated water is an eco-friendly way of solving anthropogenic contamination.
• Development of artificial beachrock using watermelon seeds as a source of urease

  Md. Al Imran, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  Proceedings of the Tenth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2020) 356 - 361 2020/11 [Refereed][Not invited]
  
• Evaluation on the performance of MICP treated slope soil under acid rain environment

  Sivakumar Gowthaman, Arash Mohsenzadeh, Kazunori Nakashima, Hiromi Nakamura, Satoru Kawasaki

  Proceedings of the Tenth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2020) 82 - 87 2020/11 [Refereed][Not invited]
  
• Mechanical strength of peat soil treated by fiber incorporated microbial cementation

  Meiqi Chen, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Tenth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2020) 41 - 46 2020/11 [Refereed][Not invited]
  
• Enzyme Induced Biocementation Using Watermelon Seed as a Source of Urease

  Md Al Imran, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the First International Conference (Online) on Microbial Biotechnology in Construction Materials and Geotechnical Engineering (MBCMG2020) 2020/11 [Refereed][Not invited]
  
• Mechanical Strength of Organic Soil Treated by Fiber Incorporated Microbial Cementation

  Sivakumar Gowthaman, Pahala Ge Nishadi Nayanthara, Kazunori Nakashima, Satoru Kawasaki, Atsuko Sato

  Proceedings of the First International Conference (Online) on Microbial Biotechnology in Construction Materials and Geotechnical Engineering (MBCMG2020) 2020/11 [Refereed][Not invited]
  
• Control of aquifer weathering degree to the groundwater chemical composition in Wates Coastal Aquifer, Yogyakarta, Indonesia

  Heru Hendrayana, Phyu Phyu Thin, Wahyu Wilopo, Satoru Kawasaki

  E3S Web of Conferences, The 1st Geosciences and Environmental Sciences Symposium (ICST 2020) 200 02005 - 02005 2020/10/23 [Refereed][Not invited]
   

  The studied coastal aquifer has been encountered a complex hydrochemical evolution. Interesting aspect is the occurrence of groundwater facies with different water chemistries in close proximity to each other. Water salinity is reported from local parts away from shore. This research was conducted for assessment of aquifer weathering and its control on groundwater chemistry. An investigation of major ions in 27 water samples was performed with geostatistics, graphical method, mineral saturation index and mass balance transport to identify the groundwater evolution. Geochemical analysis of sediments was made of 8 samples, to estimate the weathering degree using chemical index of alteration and chemical index of weathering. Silicate dissolution was promoted by low weathering, which was reflected in low ions dominated by calcium and bicarbonate in fresh water. It leaded to fine sands. Silts were dominant under moderate weathering. Sodium and calcium were higher than fresh water. Bicarbonate was still highest concentration. Main water was the mixed type which was indicated by moderate ions. Clays were formed by high weathering. Water salinity with highest dissolved solids was caused by halite dissolution and calcium adsorption on clays. Overall, groundwater chemistry in the study area is locally characterized by prevailing lithology in grouping patterns.
• The Influence of the Addition of Plant-Based Natural Fibers (Jute) on Biocemented Sand Using MICP Method

  Md Al Imran, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Materials 13 (18) 4198  2020/09 [Refereed][Not invited]
  
• The Utilization of Agricultural Waste as Agro-Cement in Concrete: A Review

  Jing He, Satoru Kawasaki, Varenyam Achal

  Sustainability 12 (17) 6971 - 6971 2020/08/27 [Refereed][Not invited]
   

  Concrete, as the world’s most implemented construction material, is increasingly being used because of the rapid development of industrialization and urbanization. Limited resources and progressive depravation of the environment are forcing scientific efforts to seek alternative and effective materials from large amounts of natural resources as additives in the partial replacement of cement. Cement is a main constituent of concrete. To solve and minimize environmental issues, research works attempting to employ the wide availability of agricultural wastes, such as sugar cane bagasse, rice husk, sugar cane straw, and palm oil fuel, among others, into cement, and to finally bring sustainable and environmentally friendly properties to concrete are being examined. Agro-waste materials are crushed into fine and coarse aggregates or are burnt into ash, and are then mixed with cement, which is known as agro-cement. The replacement of aggregates, either partially or fully, is also deemed as a sustainable material in construction. This paper mainly reviews the current research on agro-cement that has been researched and applied for the enhancement of the strength and durability of concrete. It further summarizes the relevant knowledge and techniques, while providing optimal parameters for applying agricultural wastes in concrete.
• Freeze-thaw durability and shear responses of cemented slope soil treated by microbial induced carbonate precipitation

  Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Soils and Foundations 60 (4) 840 - 855 0038-0806 2020/08 [Refereed][Not invited]
  
• Biological route to fabricate silica on cellulose using immobilized silicatein fused with a carbohydrate-binding module

  Kasun Godigamuwa, Kazunori Nakashima, Junnosuke Okamoto, Satoru Kawasaki

  Biomacromolecules 1525-7797 2020/06/16 [Refereed][Not invited]
  
• Influence of Wet-Dry and Freeze-Thaw Cycles on the Physical and Mechanical Properties of MICP Treated Slope Soil

  S. Gowthaman, K. Nakashima, H. Nakamura, S. Kawasaki

  Proceedings of the 54th U.S. Rock Mechanics/Geomechanics Symposium ARMA-2020-1119 2020/06 [Refereed][Not invited]
  
• Innovative Approach for Addressing Coastal Erosion Protection Using Microbial Induced Carbonate Precipitation

  Md Al Imran, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  European Geosciences Union General Assembly 2020 2020/05 [Refereed][Not invited]
  
• A Feasibility Investigation for Developing Artificial Beachrocks: A Potential Measure for Coastal Protection in Southeast Yogyakarta Coast, Indonesia

  Lutfian Rusdi Daryono, Kazunori Nakashima, Satoru Kawasaki, Koichi Suzuki, Anastasia Dewi Titisari, Didit Hadi Barianto, Imam Suyanto, Arief Rahmadi

  European Geosciences Union General Assembly 2020 2020/05 [Refereed][Not invited]
  
• Cellulose-metallothionein biosorbent for removal of Pb(II) and Zn(II) from polluted water

  Wilson Mwandira, Kazunori Nakashima, Yuki Togo, Tsutomu Sato, Satoru Kawasaki

  Chemosphere 246 125733  2020/05 [Refereed][Not invited]
  
• Investigation of natural beachrock and physical-mechanical comparison with artificial beachrock induced by MICP as a protective measure against beach erosion at Yogyakarta, Indonesia

  Lutfian R. Daryono, Kazunori Nakashima, Satoru Kawasaki, Koichi Suzuki, Imam Suyanto, Arief Rahmadi

  Geosciences 10 (4) 143  2020/04 [Refereed][Not invited]
  
• A novel metal adsorbent composed of hexa-histidine tag and carbohydrate-binding module on cellulose

  Yuki Togo, Kazunori Nakashima, Wilson Mwandira, Satoru Kawasaki

  Analytical Sciences 36 (4) 459 - 464 2020/04 [Refereed][Not invited]
  
• Microbial Leaching of Iron from Hematite: Direct or Indirect Elution

  Apichaya Aneksampant, Kazunori Nakashima, Satoru Kawasaki

  Materials Transactions 61 (2) 396 - 401 2020/02 [Refereed][Not invited]
  
• Sediment characteristics of beachrock: A baseline investigation based on microbial induced carbonate precipitation at Krakal-Sadranan Beach, Yogyakarta, Indonesia

  Lutfian Rusdi Daryono, Kazunori Nakashima, Satoru Kawasaki, Anastasia Dewi Titisari, Didit Hadi Barianto

  Applied Sciences 10 (2) 520  2020/01 [Refereed][Not invited]
  
• Evolution of relative sea level in Okinawa (Japan) during Holocene

  Niki Evelpidou, Satoru Kawasaki, Anna Karkani, Giannis Saitis, Giorgio Spada, Georgios Economou

  Geografia Fisica e Dinamica Quaternaria 42 (1) 3 - 16 2019/12 [Refereed][Not invited]
  
• Laboratory conditions for maximal calcium carbonate precipitation induced by Sporosarcina pasteurii and Sporosarcina aquimarina bacteria

  Hamed A. Keykha, Afshin Asadi, Bujang B. K. Huat, Satoru Kawasaki

  Environmental Geotechnics 6 (8) 562 - 566 2019/12 [Refereed][Not invited]
  
• Feasibility study for slope soil stabilization by microbial induced carbonate precipitation (MICP) using indigenous bacteria isolated from cold subarctic region

  Sivakumar Gowthaman, Takashi Iki, Kazunori Nakashima, Koji Ebina, Satoru Kawasaki

  SN Applied Sciences 1 (11) 1480  2019/11 [Refereed][Not invited]
  
• Biocementation of Sri Lankan beach sand using locally isolated bacteria: A baseline study on the effect of segregated culture media

  Pahala Ge Nishadi Nayanthara, Anjula Buddhika Nayomi Dassanayake, Kazunori Nakashima, Satoru Kawasaki

  International Journal of GEOMATE 17 (63) 55 - 62 2019/11 [Refereed][Not invited]
  
• A novel sustainable approach for coastal erosion protection through biocementation

  Md Al Imran, Shuya Kimura, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  Applied Sciences 9 (20) 4462  2019/10 [Refereed][Not invited]
  
• A Comparative Study of Beachrock Mechanism Formation Focusing on Natural and Artificial Beachrocks: Case of Diolkos, Corinth, Greece and Sumuide, Okinawa, Japan

  Giannis Saitis, Eleni Koutsopoulou, Niki Evelpidou, Satoru Kawasaki

  The International Association of Geomorphologists (IAG) Regional Conference on Geomorphology (RCG2019) P.2.05 2019/09 [Refereed][Not invited]
  
• Engineered Escherichia coli cell capable of specific binding to metal surface

  K. Nakashima, Y. Iwata, S. Kawasaki

  ACS Fall 2019 National Meeting & Exposition, San Diego, United States 2019/08 [Refereed][Not invited]
  
• Microbially induced carbonate precipitation assisted by poly-L-lysine: ecofriendly approach inspired by nature

  T.H.K. Nawarathna, K. Nakashima, S. Kawasaki

  ACS Fall 2019 National Meeting & Exposition, San Diego, United States 2019/08 [Refereed][Not invited]
  
• Beachrock identification using geology and geophysical approaches in Indonesia

  Daryono L. R, Nakashima K, Kawasaki S, Titisari A. D, Barianto D. H, Suyanto I, Rahmadi A

  Proceedings of International Symposium on Earth Resources Management and Environment, ISERME 2019 51 - 59 2019/08 [Refereed][Not invited]
  
• Microbial Induced Carbonate Precipitation Using a Native Inland Bacterium for Beach Sand Stabilization in Nearshore Areas

  Pahala Ge Nishadi Nayanthara, Anjula Buddhika Nayomi Dassanayake, Kazunori Nakashima, Satoru Kawasaki

  Applied Sciences 9 (15) 3201  2019/08 [Refereed][Not invited]
  
• Solidification of sand by Pb(II)-tolerant bacteria for capping mine waste to control metallic dust: Case of the abandoned Kabwe Mine, Zambia.

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Meki Chirwa, Kawawa Banda, Imasiku Nyambe, Shouta Nakayama, Hokuto Nakata, Mayumi Ishizuka

  Chemosphere 228 17 - 25 2019/08 [Refereed][Not invited]
   

  Environmental impacts resulting from historic lead and zinc mining in Kabwe, Zambia affect human health due to the dust generated from the mine waste that contains lead, a known hazardous pollutant. We employed microbially induced calcium carbonate precipitation (MICP), an alternative capping method, to prevent dust generation and reduce the mobility of contaminants. Pb-resistant Oceanobacillus profundus KBZ 1-3 and O. profundus KBZ 2-5 isolated from Kabwe were used to biocement the sand that would act as a cover to prevent dust and water infiltration. Sand biocemented by KBZ 1-3 and KBZ 2-5 had maximum unconfined compressive strength values of 3.2 MPa and 5.5 MPa, respectively. Additionally, biocemented sand exhibited reduced water permeability values of 9.6 × 10-8 m/s and 8.9 × 10-8 m/s for O. profundus KBZ 1-3 and KBZ 2-5, respectively, which could potentially limit the entrance of water and oxygen into the dump, hence reducing the leaching of heavy metals. We propose that these isolates represent an option for bioremediating contaminated waste by preventing both metallic dust from becoming airborne and rainwater from infiltrating into the waste. O. profundus KBZ 1-3 and O. profundus KBZ 2-5 isolated form Kabwe represent a novel species that has, for the first time, been applied in a bioremediation study.
• Microbial induced slope surface stabilization using industrial-grade chemicals: A preliminary laboratory study

  Sivakumar Gothaman, Shumpei Mitsuyama, Kazunori Nakashima, Masahiro Komatsu, Satoru Kawasaki

  International Journal of GEOMATE 17 (60) 110 - 116 2019/08 [Refereed][Not invited]
  
• Zinc and Lead Biosorption by Oceanobacillus Profundus Kbz 3-2: a Bacterial Strain Resistant to Metals Isolated from Metal polluted Soils in Kabwe, Zambia

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Meki Chirwa, Kawawa Banda, Imasiku Nyambe, Shouta Nakayama, Mayumi Ishizuka

  Proceedings of the 14th Asian Congress on Biotechnology (ACB2019) 2019/07 [Refereed][Not invited]
  
• Biological Control of Filament Formation Composed of Silica-polymerizing Enzymes

  Kazunori Nakashima, Junnosuke Okamoto, Satoru Kawasaki

  Proceedings of the 14th Asian Congress on Biotechnology (ACB2019) 2019/07 [Refereed][Not invited]
  
• Chitosan enhances calcium carbonate precipitation and solidification mediated by bacteria

  Thiloththama Hiranya Kumari Nawarathna, Kazunori Nakashima, Satoru Kawasaki

  International Journal of Biological Macromolecules 133 867 - 874 2019/07 [Refereed][Not invited]
  
• Bio-cementation for Slope Soil Stabilization againstSurface Erosion: A Bench-scale Preliminary Investigation

  S. Gowthaman, K. Nakashima, K. Ebina, S. Kawasaki

  Proceedings of the 53rd US Rock Mechanics/Geomechanics Symposium 2019/06 [Refereed][Not invited]
  
• Development of small scale biocemented rocks based on natural beachrock cement characteristics as a novel approach towards coastal erosion mitigation

  P. G. N. Nayanthara, A. B. N. Dassanayake, K. Nakashima, S. Kawasaki

  Proceedings of the 53rd US Rock Mechanics / Geomechanics Symposium 2019/06 [Refereed][Not invited]
  
• A minerochemical cement study of a beachrock slab: The case study of Peristeria, Salamis Island

  Saitis G, Evelpidou N, Kawasaki S, Koutsopoulou E, Komi A

  Proceedings of the 15th International Congress of the Goelogical Society of Greece 2019/05 [Refereed][Not invited]
  
• Ecofriendly calcium phosphate and calcium bicarbonate biogrouts

  Volodymyr Ivanov, Viktor Stabnikov, Satoru Kawasaki

  Journal of Cleaner Production 218 328 - 334 2019/05 [Refereed][Not invited]
  
• Efficacy of biocementation of lead mine waste from the Kabwe Mine site evaluated using Pararhodobacter sp.

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Kawawa Banda, Meki Chirwa, Imasiku Nyambe, Shouta Nakayama, Mayumi Ishizuka

  Environmental Science and Pollution Research 26 15653 - 15664 2019/04 [Refereed][Not invited]
  
• Biogeotechnical approach for slope soil stabilization using locally isolated bacteria and inexpensive low-grade chemicals: A feasibility study on Hokkaido expressway soil, Japan

  Sivakumar Gothaman, Shumpei Mitsuyama, Kazunori Nakashima, Masahiro Komatsu, Satoru Kawasaki

  Soils and Foundations 59 (2) 484 - 499 2019/04 [Refereed][Not invited]
  
• Factors affecting the urease activity of native ureolytic bacteria isolated from coastal areas

  Md Al Imran, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  Geomechanisc and Engineering, An International Journal 17 (5) 421 - 427 2019/04 [Refereed][Not invited]
  
• Biogeochemical simulation of microbially induced calcite precipitation with Pararhodobacter sp. strain SO1

  Masaru Akiyama, Satoru Kawasaki

  Acta Geotechnica 14 (3) 685 - 696 2019/03 [Refereed][Not invited]
  
• Environmental safety and biosafety in construction biotechnology

  Volodymyr Ivanov, Viktor Stabnikov, Olena Stabnikova, Satoru Kawasaki

  World Journal of Microbiology and Biotechnology 35 (26) 1 - 11 2019/02 [Refereed][Not invited]
  
• Ammonium-free carbonate-producing bacteria as an ecofriendly soil biostabilizer

  Keykha, H. A, Mohamadzadeh, H, Asadi, A, Kawasaki, S

  Geotechnical Testing Journal 42 (1) 19 - 29 2019/01 [Refereed][Not invited]
  
• Geological spatial plan toward groundwater resources in Kertek, Wonosobo Basin, Central Java, Indonesia

  L.R. Daryono, M.S.D. Wijayaningsih, A. Hendratno, M. Nukman, E. Hartantyo, S. Kawasaki

  Journal of Degraded and Mining Lands Management 6 (2) 1595 - 1608 2019/01 [Refereed][Not invited]
  
• Evaluating possible avenues for soil improvement by biocementation in Sri Lanka: A preliminary investigation

  P. G. N. Nayanthara, A. B, N. Dassanayake, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Eighth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2018) 759 - 764 2018/11 [Refereed][Not invited]
  
• Bio-inspired stabilization of embankment soil mediating Psychrobacillus sp. and low-grade chemicals: Preliminary laboratory investigation

  Sivakumar Gowthaman, Shumpei Mitsuyama, Kazunori Nakashima, Masahiro Komatsu, Satoru Kawasaki

  Proceedings of the Eighth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2018) 163 - 168 2018/11 [Refereed][Not invited]
  
• Electricity generation from rice bran by a microbial fuel cell and the influence of hydrodynamic cavitation pretreatment

  Yuta Yoshimura, Kazunori Nakashima, Masaji Kato, Kengo Inoue, Fumiyoshi Okazaki, Hitoshi Soyama, Satoru Kawasaki

  ACS Omega 3 (11) 15267 - 15271 2470-1343 2018/11 [Refereed][Not invited]
   

  Single-chamber microbial fuel cells (MFCs) were constructed using rice bran (carbon source) and pond bottom mud (microbial source). The total electric charge obtained in the MFC combining rice bran with pond bottom mud was four times higher than that in MFC using only rice bran. Phylogenetic analyses revealed dominant growth of fermentative bacteria such as Bacteroides and Clostridium species, and exoelectrogenic Geobacter species in the anode biofilms, suggesting that mutualism of these bacteria is a key factor for effective electricity generation in the MFC. Furthermore, rice bran, consisting of persistent polysaccharide, was pretreated by the hydrodynamic cavitation system to improve the digestibility and enhance the efficiency in MFC, resulting in 26% increase in the total production of electricity.
• Bio-based cementation using urease-producing bacteria: Sand solidification and kinetics

  K. Nakashima, M. Fujita, T. H. K. Nawarathna, S. Kawasaki

  New Biotechnology 44 s154  2018/10 [Refereed][Not invited]
  
• Comparative characteristics of cement materials in natural and artificial beachrocks using a petrographic method

  L. R. Daryono, A. D. Titisari, I. W. Warmada, S. Kawasaki

  Bulletin of Engineering Geology and the Environment 2018/09 [Refereed][Not invited]
  
• Effects of various factors on carbonate particle growth using ureolytic bacteria

  Md. Al Imran, Mai Shinmura, Kazunori Nakashima, Satoru Kawasaki

  Materials Transactions 59 (9) 1520 - 1527 2018/09 [Refereed][Not invited]
  
• A preliminary investigation on isolation and identification of marine bacteria for biocementation in nearshore environments

  Nayanthara P. G. N, Dassanayake A. B. N, Nakashima K, Kawasaki S

  Proceedings of International Symposium on Earth Resources Management and Environment, ISERME 2018 111 - 118 2018/08 [Refereed][Not invited]
  
• Experimental optimization of biocement formation: Alternative countermeasure for surface erosion of cut slope

  Gowthaman S, Nakashima K, Ebina K, Kawasaki S

  Proceedings of International Symposium on Earth Resources Management and Environment, ISERME 2018 97 - 103 2018/08 [Refereed][Not invited]
  
• Soil improvement using plant-derived urease-induced calcium carbonate precipitation

  R. A. N. Dilrukshi, Kazunori Nakashima, Satoru Kawasaki

  Soils and Foundations 58 (4) 894 - 910 2018/08 [Refereed][Not invited]
  
• Applicability of coastal ureolytic bacteria to coastal protection in Greece

  Md. Al Imran, Kazunori Nakashima, Niki Evelpidou, Satoru Kawasaki

  2018 International Conference on Geomechanics and Engineering (ICGE18) 2018/08 [Refereed][Not invited]
  
• Effects of cationic polypeptide on CaCO3 crystallization and sand solidification by microbial-induced carbonate precipitation

  Thiloththama H. K. Nawarathna, Kazunori Nakashima, Masahiro Fujita, Momoko Takatsu, Satoru Kawasaki

  ACS Sustainable Chemistry and Engineering 6 (8) 10315 - 10322 2018/07 [Refereed][Not invited]
  
• Assessment of groundwater facies in Wates coastal area, Kulon Progo, Yogyakarta, Indonesia

  Phyu Phyu Thin, Heru Hendrayana, Wahyu Wilopo, Satoru Kawasaki

  Journal of Degraded and Mining Lands Management 5 (4) 1389 - 1401 2018/07 [Refereed][Not invited]
  
• A state-of-the-art review on soil reinforcement technology using natural plant fiber materials: Past findings, present trends and future directions

  Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki

  Materials 11 (4) 553  1996-1944 2018/04/04 [Refereed][Not invited]
   

  Incorporating sustainable materials into geotechnical applications increases day by day due to the consideration of impacts on healthy geo-environment and future generations. The environmental issues associated with conventional synthetic materials such as cement, plastic-composites, steel and ashes necessitate alternative approaches in geotechnical engineering. Recently, natural fiber materials in place of synthetic material have gained momentum as an emulating soil-reinforcement technique in sustainable geotechnics. However, the natural fibers are innately different from such synthetic material whereas behavior of fiber-reinforced soil is influenced not only by physical-mechanical properties but also by biochemical properties. In the present review, the applicability of natural plant fibers as oriented distributed fiber-reinforced soil (ODFS) and randomly distributed fiber-reinforced soil (RDFS) are extensively discussed and emphasized the inspiration of RDFS based on the emerging trend. Review also attempts to explore the importance of biochemical composition of natural-fibers on the performance in subsoil reinforced conditions. The treatment methods which enhances the behavior and lifetime of fibers, are also presented. While outlining the current potential of fiber reinforcement technology, some key research gaps have been highlighted at their importance. Finally, the review briefly documents the future direction of the fiber reinforcement technology by associating bio-mediated technological line.
• Fly ash incorporated with biocement to improve strength of expansive soil

  Mengmeng Li, Chaolin Fang, Satoru Kawasaki, Varenyam Achal

  Scientific Reports 8:2565 2018/02 [Refereed][Not invited]
  
• Bio-consolidation of cracks in masonry cement mortars by Acinetobacter sp. SC4 isolated from a karst cave

  Mengmeng Li, Chaolin Fang, Satoru Kawasaki, Minsheng Huang, Varenyam Achal

  International Biodeterioration and Biodegradation 141 94 - 100 0964-8305 2018 [Refereed][Not invited]
   

  Microbially induced carbonate precipitation (MICP) is one of techniques for consolidation of cementitious materials however, limited biodiversity and inadequate information on its application suggests further extensive research in this area. In this study, bacteria with ability to precipitate carbonate, preferably CaCO3, were isolated from Yixing Shanjuan Cave, China after analyzing bacterial diversity using Illumina MiSeq sequencing the V3-V4 region of 16S rRNA gene. A total of 58,712 effective 16S rRNA gene sequences were obtained, classified into 31 bacterial phyla. One of the highest urease-producing bacterium, Acinetobacter sp. SC4, was then used in consolidation of cracks created in masonry cement mortars. The bio-consolidation led to significant improvement in compressive strength and reduction in water absorption of mortars. It formed calcite observed under scanning electron microscopy, which were in agreement with X-ray diffraction and thermogravimetric analysis. The presented work is the first extensive study on Acinetobacter sp. induced carbonate precipitation in MICP related research.
• Enhancement of microbially induced carbonate precipitation using organic biopolymer

  Thiloththama Hiranya Kumari Nawarathna, Kazunori Nakashima, Satoru Kawasaki

  International Journal of GEOMATE 14 (41) 7 - 12 2186-2982 2018 [Refereed][Not invited]
   

  Microbially induced carbonate precipitation (MICP) by using ureolytic bacteria is a novel and environmentally friendly way to treat the un-cemented sand. It was implemented successfully in number of geotechnical applications. Use of organic additives to improve the MICP process is a novel and interesting approach. In this research, effect of the cationic biopolymer poly-l-lysine on the MICP process was investigated by using ureolytic bacteria Pararhodobacter sp. Urea hydrolysis by the bacteria in the presence of CaCl2 was conducted with the addition of the polymer under different conditions. Morphology of the precipitate of CaCO3 after oven dried was analyzed by using the scanning electron microscope. Bell-shaped curve was obtained for the variation between the amount of the precipitate with the increase of the amount of the poly-l-lysine. Poly-L-lysine gives higher amount of precipitate than conventional MICP process and morphology of the crystals changed drastically from well-developed rhombohedral crystals to ellipsoidal shaped aggregates.
• Factors Affecting Sand Solidiflcation Using MICP with Pararhodobacter sp.

  G. G.N.N. Amarakoon, Satoru Kawasaki

  Materials Transactions 59 (1) 72 - 81 1345-9678 2018 [Refereed][Not invited]
   

  Biomineralization is an environmentally friendly technology for improving soil-engineering properties. One of the most common biomineralization processes is microbially induced calcite precipitation (MICP). In this study, sand solidification tests were conducted using Pararhodobacter sp., which is a local ureolytic bacteria obtained from the sand near beach rock in Okinawa, Japan. The goal of this study was to solidify a specimen having an estimated unconfined compressive strength (UCS) of more than several MPa to improve soil properties and investigate the influence of various factors on the engineering properties of treated soil catalyzed by ureolytic bacteria (curing temperature, injection interval of cementation solution, Ca2+ concentration, curing time, bacterial population, re-injection of bacteria and particle size of sand). Model test specimens were cemented up to an estimated UCS of 10 MPa after 14 days under the following conditions: a curing temperature of 30°C, an injection interval of 1 day, and a Ca2+ concentrations in cementation solution of 0.5 M. Multiple regression analysis showed that the relevant conditions for estimating UCS were test period, D (days), and Ca2+ concentration of the cementation solution, Cca (M). The formula for predicting the estimated UCS (qeu (MPa)) was qeu = 13.99 Cca + 0.37 D-0.09. Overall, the results of this study will contribute to the application of a new technique to sand improvement and bio-stimulation.
• Bioremediation of lead-contaminated mine waste by Pararhodobacter sp based on the microbially induced calcium carbonate precipitation technique and its effects on strength of coarse and fine grained sand

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki

  ECOLOGICAL ENGINEERING 109 (Part A) 57 - 64 0925-8574 2017/12 [Refereed][Not invited]
   

  Lead (Pb2+) is a toxic heavy metal that has a severe negative effect on human health and the environment. Physical, chemical and biological remediation techniques have long been used to remediate lead contamination. However, because of the great danger posed by lead contamination, there is increasing interest to apply ecofriendly and sustainable methods to remediate lead. Therefore, this study was conducted to use the microbially induced calcium carbonate precipitation (MICP) technique in conjunction with the bacterium Pararhodobacter sp. to bioremediate lead. Laboratory scale experiments were conducted and complete removal of 1036 mg/L of Pb2+ was achieved. These results were further confirmed by scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis, which indicated coprecipitation of calcium carbonate (CaCO3) and lead. The unconfined compressive strength increased with an increase in injection interval with maximum unconfined compressive strength of 1.33 MPa for fine sand, 2.87 MPa for coarse sand and 2.80 MPa for mixed sand. For Pararhodobacter sp. to efficiently induce lead immobilisation the bacterial interval required is four times with a calcium and urea concentration of 0.5 M and bacterial concentration of 109 cfu/mL. Very few low-cost in situ heavy metal treatment processes for lead bioremediation are available; therefore, bioimmobilization of lead by MICP has the potential for application as a low-cost and eco-friendly method for heavy metal remediation.
• Microbially induced carbonate precipitation for expressway slope protection

  Mitsuyama, S, Nakashima, K, Komatsu, M, Kawasaki, S

  Abstract Proceedings of the 1st International KAMPAI Symposium on Sustainable Management of Resources and Environment in the 21st Century 23  2017/11 [Refereed][Not invited]
  
• Effect of cationic bio-polymer on CaCO3 crystallization by microbe

  T.H.K. Nawarathna, Kazunori Nakashima, Satoru Kawasaki

  Abstract Proceedings of the 1st International KAMPAI Symposium on Sustainable Management of Resources and Environment in the 21st Century 24  2017/11 [Refereed][Not invited]
  
• Immobilization of Lead-Contaminated Mine Waste by Pararhodobacter sp.

  Mwandira, W, Nakashima, K, Kawasaki, S, Chirwa, M, Banda, K.E, Nyambe, I.A

  Abstract Proceedings of the 1st International KAMPAI Symposium on Sustainable Management of Resources and Environment in the 21st Century 39  2017/11 [Refereed][Not invited]
  
• Effect of Organic biopolymer on the microbially induced carbonate precipitation and its morphology

  Thiloththama Hiranya Kumari Nawarathna, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Seventh International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2017) 7 (1) 719 - 724 2017/11 [Refereed][Not invited]
  
• Usefulness of artificial beachrock and geotextile tube technology

  Md. Al Imran, Kazanori Nakashima, Satoru Kawasaki

  Proceedings of the Seventh International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2017 7 (1) 423 - 428 2017/11 [Refereed][Not invited]
  
• Application of numerical simulation of microbial reaction to biogrout with ureolytic bacteria

  Masaru Akiyama, Satoru Kawasaki

  Japanese Geotechnical Journal 公益社団法人 地盤工学会 12 (3) 337 - 349 2017/09 [Refereed][Not invited]
   

  Reproduction of solidification process by biogrout with ureolytic bacteria was conducted using numerical simulation of microbial reaction for contributing to the environmental impact assessment and the proper construction design according to ground conditions in the practical utilization of the biogrout. Based on results of the urease activity measurement, the reaction rate constant and the half saturation concentration in the reproduction analysis was determined to 1×10^-8 mol/mg/sec and 0.635 mol/L, respectively. Mineral precipitation in the simulation matched actual mineral precipitation in the syringe-scale solidification test under the constraint condition of calcite precipitation only. Multiple injection procedure of solidification solution contained urea were expressed by setting sequential analysis, in which the initial condition of the current analysis succeeds the amount of calcite in the previous step. In addition to that, the changes of Ca²⁺ concentration in outlet solution were reproduced by introducing the “adjustment exponent” in consideration of the decrease in the amount of active microorganisms. In that case, the correlation coefficient between the measured and analyzed values was 0.9232. The above results indicate that numerical simulation of microbial reaction related to calcite precipitation can reproduce the reaction process of biogrout with ureolytic bacteria, and can predict the strength development and construction management at the time of biogrout construction.
• Efect of organic bio-polymer on bio-mineralization of CaCO3

  T.H.K. Hiranya, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of International Symposium on Earth Resources Management and Environment, ISERME 2017 59 - 66 2017/08 [Refereed][Not invited]
  
• Bioremediation of lead-contaminated mine waste using microbially induced carbonate precipitation

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of International Symposium on Earth Resources Management and Environment, ISERME 2017 21 - 25 2017/08 [Refereed][Not invited]
  
• Whole-cell evaluation of urease activity of Pararhodobacter sp isolated from peripheral beachrock

  Masahiro Fujita, Kazunori Nakashima, Varenyam Achal, Satoru Kawasaki

  BIOCHEMICAL ENGINEERING JOURNAL 124 1 - 5 1369-703X 2017/08 [Refereed][Not invited]
   

  Pararhodobacter sp. SW is a urease-producing bacterium and can be used for microbial induced calcium carbonate precipitation (MICP). In the present study, microbial cells are directly used for the analysis of urease activity without extraction or purification of urease. The whole-cell evaluation of the bacteria provides important and comprehensive information on urease activity because the bacterial cells are directly used in biomineralization process. The urease activity of Pararhodobacter sp. increased with cell growth during cultivation and the bacteria maintained its enzyme activity even after 15-days culture. High urease activity was obtained at relatively high temperature around 60 degrees C and neutral pH around 8. It is revealed that urease was not secreted in culture medium but would accumulate in/on the cell, and resuspended cells obviously showed urease activity. Meanwhile, the enzyme activity was detected in a soluble fraction of cell lysate. Furthermore, clear band based on urease activity was observed in soluble fraction of cell lysate in native PAGE analysis followed by activity staining. These findings will contribute to the efficient biocementation using this ureolytic bacteria. (c) 2017 Elsevier B.V. All rights reserved.
• Solubilization and functional evaluation of silica-polymerizing enzyme

  Hidetoshi Oguri, Kazunori Nakashima, Satoru Kawasaki

  The 13th the Asian Congress on Biotechnology 2017 (ACB2017) 2017/07 [Refereed][Not invited]
  
• Combination technology of geotextile tube and artificial beachrock for coastal protection

  Md. Al Imran, Kazunori Nakashima, Satoru Kawasaki

  International Journal of GEOMATE 13 (39) 67 - 72 2186-2982 2017 [Refereed][Not invited]
   

  In recent years, traditional forms of river and coastal structures have become very expensive to build and maintain, because of the shortage of natural rock. Therefore, the materials used in hydraulic and coastal structures are changing from traditional rubble and concrete systems to cheaper, sustainable, and eco-friendly materials and systems such as artificial rock, gabion, slags, geosynthetics, and so on. Moreover, shorelines are being continually eroded by the wave action of the sea, and the river and coastal structures are frequently damaged by both anthropogenic and natural causes such as over wash and storm. How to deal with eroding coastal problems is a main topic of this article. Recently, artificial beachrock and geotextile tube technology has changed from being an alternative construction technique and, in fact, has advanced to become the prime solution of choice. Therefore, the objectives of the present study is to find out the feasibility to protect coastal erosion in Asia along with using artificial beachrock and geotextile tube technology in a cheaper, sustainable and eco-friendly way.
• Evaluation of porosity in biogrouted sand using microfocus X-ray CT

  Shumpei Mitsuyama, Kazunori Nakashima, Satoru Kawasaki

  International Journal of GEOMATE 12 (31) 71 - 76 2186-2982 2017 [Refereed][Not invited]
   

  Biogrouting is a method employed for ground improvement based on microbially induced calcium carbonate precipitation. It is commonly believed that biogrout has environmental and economic benefits. However, there remains the need to clearly understand the internal structure of biogrouted soil. In this study, we use microfocus X-ray computed tomography (CT) to evaluate the porosity in biogrouted sand. X-ray CT is useful as a non-distractive inspection tool. First, we prepare small specimens using coral sand at different dilution rates of culture solution. After carrying out a solidification test for 2 wks., we perform an unconfined compressive strength (UCS) test and measure the porosity of the specimens. Our aim is to investigate the influence of the dilution rate on the UCS and the porosity of sand specimens. The results show that a lower dilution rate resulted in a lower sand-specimen porosity and an increase in the UCS. We investigate the precipitation that fills a void. Then, we investigate the relationship between UCS and the ratio of porosity. There was a negative correlation between UCS and porosity, which closely agrees with previous research. We confirm the validity of the result, and we determine the UCS from the porosity.
• Effect of acid rain on geotechnical properties of residual soils

  Zeinab Bakhshipour, Afshin Asadi, Bujang B. K. Huat, A. Sridharan, Satoru Kawasaki

  SOILS AND FOUNDATIONS 56 (6) 1008 - 1020 0038-0806 2016/12 [Refereed][Not invited]
   

  In this study, the effect of acid rain on the physico-chemical and microstructural properties of two different residual soils was investigated. In order to reproduce the process of soil-acid rain-chemical interaction, an infiltration setup was fabricated. The samples were then infiltrated by different pH levels of acid rain, and for different fluxes of acid rain equivalent to the precipitation, for 1-20 years. The compressive strength, consistency limit, compaction characteristics, and coefficient of permeability were evaluated, to investigate the mechanical changes of the soils after being exposed to acid rain. In addition, zeta potential, atomic adsorption spectroscopy (AAS), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were carried out to identify the underlying controlling mechanisms. The results showed that low pH and high fluxes of acid rain led to a reduction in soil strength and maximum dry density as well as an increase in the coefficient of permeability, liquid limit, and optimum moisture content of the soil. The SEM, EDX, and atomic absorption analysis of the soils confirmed the reduction in the concentration of elements, and the loose structure for both soils due to the effects of acid rain. (C) 2017 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V.
• Evaluation of porosity in biogrouted sand using microfocus X-ray CT

  Shumpei Mitsuyama, Kazunori Nakashima, Satoru Kawasaki

  Proceedings of the Sixth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2016) 145 - 150 2016/11 [Refereed][Not invited]
  
• Effects of various powders on strength reinforcement of calcium phosphate compounds precipitated in sand specimens

  Dilrukshi, R.A.N, Kawasaki, S

  Abstract Proceedings of International Doctoral Symposium on Sustainable Management of Resources and Environment in the 21st Century 8  2016/11 [Refereed][Not invited]
  
• Anthropogenic Beachrock for Eco-Environment Shoreline Development

  L. R. Daryono, A. D. Titisari, I. W. Warmada, S. Kawasaki

  The 2nd International Conference on Science and Technology 2016 (ICST2016) 2016/10 [Refereed][Not invited]
  
• Strength reinforcement of sand test specimens cemented with calcium phosphate compounds and different powders

  R.A.N. Nadeeka, S. Kawasaki

  Proceedings of the 9th Asian Rock Mechanics Symposium ARMS9-RMC3-P86  2016/10 [Refereed][Not invited]
  
• Coral sand solidification test through microbial calcium carbonate precipitation using Pararhodobacter sp.

  Md. Nakibul, Hasan Khan, S. Shimazaki, S. Kawasaki

  International Journal of GEOMATE 11 (26) 2665 - 2670 2016/10 [Refereed][Not invited]
  
• Comparison of Cementation Mechanism between Natural Beachrock and Anthropogenic Beachrock, Case Study: Okinawa Island, Japan

  L. R. Daryono, A. D. Titisari, I. W. Warmada, S. Kawasaki

  The 41st Scientific Annual Meeting of Indonesian Association of Geophysicists PITHAGI2016-042  2016/09 [Refereed][Not invited]
  
• Plant-derived urease induced sand cementation used in geotechnical engineering applications

  R. A. N. Dilrukshi, Satoru Kawasaki

  Proceedings of the International Conference on Geomechanics, Geo-energy and Geo-resources IC3G 2016 Theme 7-100 - Theme 7-107 2016/09 [Refereed][Not invited]
  
• Strengthening of sand cemented with calcium phosphate compounds using plant-derived urease

  R. A. N. Dilrukshi, Jun Watanabe, Satoru Kawasaki

  International Journal of GEOMATE 11 (25) 2461 - 2467 2016/09 [Refereed][Not invited]
  
• Development of biogrouting using plant-derived urease and calcium phosphate compound

  M. Takatsu, R. A. N. Dilrukshi, S. Kawasaki

  Proceedings of the 50th US Rock Mechanics / Geomechanics Symposium ARMA 16-471  2016/06 [Refereed][Not invited]
  
• Soil reinforcement using calcium phosphate compounds

  S. Kawasaki, M. Akiyama

  ASEAN Engineering Journal, Part C 5 (1) 5 - 13 2016/06 [Refereed][Invited]
  
• Possibility for solidification of peaty soil by using microbes

  Atsuko Sato, Satoru Kawasaki, Toshiro Hata, Toshihiro Hayashi

  International Journal of GEOMATE 10 (22) 2071 - 2076 2186-2982 2016/06 [Refereed][Not invited]
   

  Peaty soil is widely distributed in Hokkaido. Untreated, it is too soft for use as a civil engineering material. Soil solidification improvement technologies that harness the metabolism of microbes in soil have recently been gaining attention. Such research and development has proceeded within and beyond Japan. The researchers investigated a technology for peat solidification that harnesses the ability of microbes inhabiting the soil of construction sites to precipitate calcium carbonate, and consideration was given to solidifying peaty soil by harnessing the ability of those microbes. Focusing on the urease activity of microbes, which has an influence on solidification of peaty soil, a soil solidification test, in which the metabolism of microbes was utilized, and an experiment, in which the degree of solidification of peaty soil was tested, were done by using peaty soil samples from Hokkaido. The two experiments found the following. 1) Microbes that have urease activity inhabit the peaty soil of Hokkaido. 2) It is possible to solidify peaty soil by enhancing the urease activity of these microbes. 3) It is possible to evaluate the degree of urease activity in peaty soil by measuring its electric conductivity.
• Study of beachrocks in East Attica

  A. Karkani, N. Evelpidou, H. Maroukian, S. Kawasaki

  Bulletin of the Geological Society of Greece 50 (1) 434 - 440 2016/05 [Refereed][Not invited]
  
• Biogrout: A Novel Binding Material for Soil Improvement and Concrete Repair

  Varenyam Achal, Satoru Kawasaki

  FRONTIERS IN MICROBIOLOGY 7 (314) 1664-302X 2016/03 [Refereed][Not invited]
  
• Microbially Induced Sand Cementation Method Using Pararhodobacter sp Strain SO1, Inspired by Beachrock Formation Mechanism

  Takashi Danjo, Satoru. Kawasaki

  MATERIALS TRANSACTIONS 57 (3) 428 - 437 1345-9678 2016/03 [Refereed][Not invited]
   

  To develop an alternative ground improvement technique in coastal areas based on bio-stimulation, we investigated sand cementation using bacteria that have been shown to enhance beachrock formation. We conducted cementation tests using Pararhodobacter sp. strain SO1, a local ureolytic bacteria originating from the sand near beachrock in Okinawa, Japan. Specifically, we attempted to cement sand specimens to unconfined compressive strength (UCS) of several MPa and establish the influence of several test conditions (curing temperature, injection interval of cementation solution, Ca2+ concentration and sodium malate concentration in the cementation solution, and test period) on the UCS. Column specimens were cemented up to UCS of 10 MPa after 28 days under the conditions (curing temperature; 30 degrees C, injection interval; 1 day, Ca2+ concentrations in cementation solution; 0.3 M). Multiple regression analysis showed that the relevant conditions for UCS were test period, D (days), and Ca2+ concentration of the cementation solution, C-ua (M). The prediction formula for UCS, q(ud) (MPa), was experimentally determined to be q(ud) = 48.3C(ca) + 0.456D - 19.51. Overall, the results of this study will contribute to the application of a new technique for coastal sand improvement and bio-stimulation.
• Sand solidification through microbially induced carbonate precipitation for erosion control: Prospects in Bangladesh

  M. N, H. Khan, S. Kawasaki, M. R. Hassan

  Journal of Environmental Science and Natural Resources 9 (1) 59 - 61 2016 [Refereed][Not invited]
  
• Sand Cementation Using the pH Dependency of Calcium Phosphate Compounds and the Addition of Various Powders

  R. A.N. Dilrukshi, S. Kawasaki

  Geotechnical Special Publication 2016- (269) 104 - 115 0895-0563 2016 [Refereed][Not invited]
   

  The effect of pH increasing ability of plant-derived urease to induce the precipitation of calcium phosphate compounds (CPCs) as CPC-biogrout (CPC-Bio) and addition of powder materials to induce the precipitation of CPCs as CPC-chemical grout (CPC-Chem) was examined separately using unconfined compressive strength (UCS) test for applying as novel, eco-friendly ground improvement methods. Initially, Toyoura sand test pieces were cemented only from CPC solutions made from stock solutions of calcium acetate and di-potassium phosphate. Subsequent sand test pieces were cemented by different concentrations of urea and CPC solution, and concentration fixed watermelon seeds extract. All test pieces were cured in an airtight container at high humidity at 25°C. Furthermore, the UCS on sand test pieces cemented with same stock solutions mentioned above with different powders such as tricalcium phosphate (TCP), magnesium phosphate (MgP), calcium carbonate (CC) and magnesium carbonate (MgC) were conducted. Maximum UCS of greater than 100 kPa was obtained after 28 days of curing for both CPC-Bio and CPC-Chem and obtained UCS was higher than the UCS of test pieces made only from CPC. pH for optimal cementation was around 8.0 and the best Ca/P ratio in CPC solutions producing the highest cementation was 0.5 for CPC-Bio.
• Factors Affecting the Improvement of Sand Properties Treated with Microbially-Induced Calcite Precipitation

  G. G.N.N. Amarakoon, S. Kawasaki

  Geotechnical Special Publication 2016- (269) 72 - 83 0895-0563 2016 [Refereed][Not invited]
   

  Bio-mineralization is an environment-friendly technology to improve soil engineering properties. One of common bio-mineralization processes is microbially induced calcite precipitation (MICP). A series of laboratory tests was conducted to produce solidification of the specimen having an estimated unconfined compressive strength (UCS) of more than several MPa, and investigate the influence of varies factors on soil properties treated with MICP. A solidification test was conducted using a syringe (30 mL) on different particle size of Mikawa sand (mean diameter: 0.6mm) and Toyoura sand (mean diameter: 0.2mm) using local ureolytic bacteria: Parahadobactor sp. isolated in Japan. The bacteria were grown up for 72 hours to increase the optical density (OD) of 600 nm (OD600). The cementation media was added and the solidification test was conducted until 14 days. After that, needle penetration tests were conducted to obtain the estimated UCS value of the specimen. The results indicated that the estimated UCS value was exceeded 3 MPa for three Mikawa sand samples: (1) sample treated by 1.0g of bacteria re-injected bacterial solution after 7 days, (2) sample treated by 1.0g of bacteria without re-injection after 7 days, and (3) sample treated with 0.1g of bacteria with re-injection.
• Experimental study on ground solidification using ureolytic bacteria

  A. Yaegashi, T. Danjo, S. Kawasaki

  第44回岩盤力学に関するシンポジウム講演集 268 - 272 2016/01 [Not refereed][Not invited]
  
• Effective use of plant-derived Urease in the field of geoenvironmental/geotechnical engineering

  R. A. N. Dilrukshi, Satoru Kawasaki

  Journal of Civil and Environmental Engineering 6 (1) 2016/01 [Refereed][Not invited]
  
• Fundamental study on peat solidification technology using microorganisms

  A. Sato, S. Kawasaki, T. Hata, T. Yamanashi, S. Nishimoto

  Journal of Japan Society of Civil Engineers, Ser.C (Geosphere Engineering) 71 (4) 427 - 439 2015/12 [Refereed][Not invited]
  
• Artificial beachrock formation through sand solidification towards the inhibit of coastal erosion in Bangladesh

  Md. Nakibul, Hasan Khan, Takashi Danjo, Satoru Kawasaki

  International Journal of GEOMATE 9 (2) 1528 - 1533 2015/12 [Refereed][Not invited]
  
• Mechanical property of sand cemented with calcium phosphate compounds using plant-derived urease

  R. A. N. Dilrukshi, J. Watanabe, S. Kawasaki

  Proceedings of the Fifth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2015) 84 - 89 2015/11 [Refereed][Not invited]
  
• Estimating urease activity in microorganism of peat based on electric conductivity

  A. Sato, S. Kawasaki, T. Hata, T. Yamanashi

  Proceedings of the Fifth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2015) 426 - 429 2015/11 [Refereed][Not invited]
  
• Coral sand solidification test through microbial carbonate precipitation using Pararhodobacter sp.

  Md. Nakibul, Hasan Khan, S. Shimazaki, S. Kawasaki

  Proceedings of the Fifth International Conference of Geotechnique, Construction Materials and Environment (GEOMATE 2015) 131 - 137 2015/11 [Refereed][Not invited]
  
• Bio-grout based on microbially induced sand solidification by means of asparaginase activity

  Mengmeng Li, Qing-Long Fu, Qiuzhuo Zhang, Varenyam Achal, Satoru Kawasaki

  SCIENTIFIC REPORTS 5 2045-2322 2015/11 [Refereed][Not invited]
   

  Bio-grout, a new ground improvement method, has been recently developed to improve the mechanical properties, decrease the permeability of porous materials, reinforce or repair cementitious materials and modify the properties of soil or sand. Bio-grout production depends on microbially induced calcite precipitation (MICP), which is driven mainly by an enzyme, urease. However, urease-based MICP process produces excessive ammonia, in addition to secondary pollution generated by urea that is used as substrate in it. In the present study, we reported asparaginase-based MICP process for sand bio-grout development using Bacillus megaterium, and results were also compared with urease-based bio-grouts. The asparaginase activity led to significantly less ammonia production compared to urease without compromising with desired properties of a novel grout. The UCS of bio-grout was obtained at 980 kPa, while the permeability was decreased substantially. The mineralogical composition of precipitated substance was identified as calcite using XRD and the crystal morphology was observed under SEM. The mass percentage of calcite in bio-grout was calculated by thermogravimetric analysis and XCT verified calcite precipitation in it. The results confirmed that biocalcification by means of bacterial asparaginase is a potential solution for geotechnical problems. The asparaginase-based MICP process could be of wider acceptance in future.
• Coral Sand Solidification Test Based on Microbially Induced Carbonate Precipitation Using Ureolytic Bacteria

  Md. Nakibul Hasan Khan, G. G. N. N. Amarakoon, Suguru Shimazaki, Satoru Kawasaki

  MATERIALS TRANSACTIONS 56 (10) 115 - 122 1345-9678 2015/10 [Refereed][Not invited]
   

  Artificial beachrock, formed by coral sand solidification through microbially induced carbonate precipitation (MICP), could provide coastal protection instead of concrete structures, and would be eco-friendly as well as help minimize costs. The present study was conducted to solidify coral sand through the MICP method by using an ureolytic bacterium (Parahodobacter sp.) isolated from peripheral beachrock. The goal was to obtain a sample with an unconfined compressive strength (UCS) of 20 MPa or more. We also aimed to examine the growth characteristics of this bacterium in the culture medium ZoBell2216E, which is commonly used for marine bacteria. In order to determine the suitability of the MICP test, growth properties of the microbial strain were observed under various culture conditions. A sand solidification test with MICP was carried out in a syringe as well as a PET cylinder. The strength of the resulting specimens was measured with the needle penetration test. The specimen solidified up to 20 MPa of the estimated UCS after 21 days of curing. For optimum growth of the bacterium, 1.0 g of the culture was added to 100 mL culture media and incubated with shaking at 160 rpm. The preferred final concentration in solidification promoting solution of both urea and CaCl2 was 0.5 M, with bacterial cell densities of 10(9) CFU/mL. In order to efficiently induce solidification, the optimum pH was 7.0 or higher, and Ca2+ concentration was maintained at 1.0 g/L. The results were enhanced by re-injecting the culture solution when the pH and Ca2+ concentrations in the specimen were not in the ideal ranges indicated above.
• Aging behaviour of organic matter decomposition and microstructure of coal using hydrogen peroxide for bio-methane production in subsurface environment

  Noritaka Aramaki, Shuji Tamamura, Sho Tanaka, Satoru Kawasaki, Yoshiaki Fujii, Katsuhiko Kaneko

  Japanese Geotechnical Journal 10 (3) 391 - 401 2015/09 [Refereed][Not invited]
  
• Sand Cementation Test using Plant-Derived Urease and Calcium Phosphate Compound

  R. A. N. Dilrukshi, Jun Watanabe, Satoru Kawasaki

  MATERIALS TRANSACTIONS 56 (9) 1565 - 1572 1345-9678 2015/09 [Refereed][Not invited]
   

  The investigation of urease containing plant species and the calcium phosphate compounds (CPCs) precipitation along with plant derived urease were performed at laboratory scale. At first, small scale laboratory samples (height, h = 10 cm & inner diameter, phi = 5 cm) were made using Toyoura sand and only from CPC solution having different Ca/P ratios to use as control samples. Afterward, another Toyoura sand test pieces were made by mixing watermelon seed extract, urea with different concentrations and CPC solution having different Ca/P ratios to study the optimal cementation. Test pieces were cured up to 28 days in an airtight container at high humidity at 25 degrees C and carried out unconfined compressive strength (UCS) test. The UCS of the sand test pieces cemented by CPC with urease containing plant extract and urea were larger than that of the test pieces without plant extract. Furthermore, the best CPC solution mixture for highest cementation was with the concentration of Ca/P ratio of 0.5. In addition, pH content was measured after UCS test. Maintaining pH around 8 in the specimen at 28 days was significant to get optimal cementation.
• Compressive strength of sand cemented with calcium phosphate compound

  G. G. N, N. Amarakoon, S. Kawasaki

  Proceedings of the International Conference on Geotechnical Engineering ICGE Colombo 2015 197 - 200 2015/08 [Refereed][Not invited]
  
• Present status of ground improvement technologies using microbial functions

  KAWASAKI Satoru

  Journal of MMIJ 131 (5) 155 - 163 2015/05 [Refereed][Not invited]
  
• Novel microbial based low energy green building material production technology

  Mengmeng Li, Satoru Kawasaki, Qiuzhuo Zhang, Varenyam Achal

  Advanced Materials Research 1090 96 - 100 2015/02 [Refereed][Not invited]
  
• Coral sand solidification test using ureolytic bacteria

  T. Danjo, S. Kawasaki, S. Shimazaki, K. Koizuka

  Geomechanics from Micro to Macro, Vols I and II 1521 - 1526 2015 [Refereed][Not invited]
   

  The use of an artificial rock modelled on beachrock is considered a novel eco-friendly countermeasure to preserve coastlines. Beachrock consists of coastal sediments from within the intertidal zone that have been cemented mainly by CaCO3. In this study, a solidification test was conducted on coral sand using local ureolytic bacteria based on a beachrock formation mechanism previously investigated at Okinawa, Japan. The experiment aimed to produce solidification of the specimen to an Unconfined Compressive Strength (UCS) of more than several MPa (1/10-1/5 of the UCS value of ordinal concrete and beachrock). Results showed that using Pararhodobacter sp., found near beachrock in Okinawa, Japan, the specimen solidified to 6.7 MPa UCS after 28 days of curing. The solidification mechanism was the stimulation of ureolysis by the bacteria and the precipitation of aragonite between sand particles.
• Formation of artificial beachrock towards inhibit of coastal erosion in Bangladesh: A review

  Md. Nakibul H. Khan, Satoru Kawasaki

  15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2015: New Innovations and Sustainability 1123 - 1127 2015 [Refereed][Not invited]
   

  Erosion in the coastal area of Bangladesh is a big point of concern. The present study was conducted to find out the protective measure from coastal erosion in Bangladesh as well as evaluate the prospects of the formation of artificial beachrock. This study was conducted based on literature survey of related works. In the coast of Bangladesh, average recession through erosion will occur 0.87m due to per 1cm sea level rise. Beachrock as well as artificial beachrocks have the potentiality to prevent such coastal erosion. Beachrock is a type of sedimentary deposit that generally occurs on the tropical and subtropical beaches as a result of intertidal lithification of loose beach sands and gravels by carbonate cementation. Beachrock in the world differs by their chemical composition but it composed mainly of CaCO3, SiO2 and Al2O3. Usually, beachrocks are formed by the cementation of CaCO3 precipitation with the influence of seawater and/or seawater evaporation as well as surface microorganisms. From the knowledge of natural beachrock formation as well as sand properties, in the future, it may possible to manufacture artificial beachrocks similar to beachrocks for erosion control purposes in Bangladesh.
• Effect on unconfined compressive strength of sand test pieces cemented with calcium phosphate compound

  G. G. N, N. Amarakoon, T. Koreeda, S. Kawasaki

  International Journal of GEOMATE 7 (2) 1069 - 1074 2014/12 [Refereed][Not invited]
  
• Effect on unconfined compressive strength of sand test pieces cemented with calcium phosphate compound by addition of scallop shell powder

  G. G. N, N. Amarakoon, T. Koreeda, S. Kawasaki

  Proceedings of the Fourth International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2014) 50 - 55 2014/11 [Refereed][Not invited]
  
• Improvement in the unconfined compressive strength of sand test pieces cemented with calcium phosphate compound

  G. G. N, N. Amarakoon, T. Koreeda, S. Kawasaki

  Proceedings of the 8th Asian Rock Mechanics Symposium 276 - 282 2014/10 [Refereed][Not invited]
  
• Effects of bacterial ureolysis and seawater evaporation on beachrock formation

  T. Danjo, S. Kawasaki, S. Shimazaki, K. Koizuka

  Proceedings of the 8th Asian Rock Mechanics Symposium 270 - 275 2014/10 [Refereed][Not invited]
  
• Microstructure of brown coal in hydrogen peroxide solution observed by employing X-ray computed tomography

  N. Aramaki, S. Tamamura, S. Shimizu, A. Ueno, Y. Ohmi, K. Kaneko, S. Tanaka, S. Kawasaki

  Proceedings of the 8th Asian Rock Mechanics Symposium 1579 - 1588 2014/10 [Refereed][Not invited]
  
• Effect of liquefaction countermeasures for sand cemented by microbial metabolism

  Y. Inagaki, M. Tsukamoto, T. Sasaki, S. Kawasaki

  Proceedings of the 8th Asian Rock Mechanics Symposium 920 - 929 2014/10 [Refereed][Not invited]
  
• Improvement in the Unconfined Compressive Strength of Sand Test Pieces Cemented with Calcium Phosphate Compound by Addition of Calcium Carbonate Powders

  G. G. N. N. Amarakoon, Takefumi Koreeda, Satoru Kawasaki

  MATERIALS TRANSACTIONS 55 (9) 1391 - 1399 1345-9678 2014/09 [Refereed][Not invited]
   

  Grouting using calcium phosphate compound (CPC) has been used for countermeasure for liquefaction in geotechnical engineering applications and it is an economical and environmental friendly technique that develops to form calcium carbonate precipitation throughout the soil, leading to an increase in soil strength. In the paper, our aim was to improve strength by adding CPC with CaCO3 (commercially found) and scallop shell (Naturally found) powder and exceed a maximum UCS of 100 kPa after 28 days of curing, which is the strength required as a countermeasure against soil liquefaction during earthquake. For that, initially Toyoura sand test pieces were cemented by CPC solutions only and cured up to 56 days and carried out unconfined compressive strength (UCS) test. Moreover, Toyoura sand test pieces were cemented by CPCs with CaCO3 (CC) powder and CPCs with scallop shell powder and cured and these specimens also analyzed with UCS tests. The UCS of the sand test pieces cemented by CPC with scallop shell powder and CC powder was higher than that of the test pieces with no added powders. In addition, a series of laboratory experiments were conducted, including pH concentration, scanning electron microscope (SEM) in order to observe the microscopic structure, density before and after curing etc. The results indicate that the density and the pH concentration of the sand test pieces cemented by CPC with scallop shell powder and CC powder were higher than that of the test pieces with no added powders.
• Segmentation of multi-phase X-ray computed tomography images

  Masaji Kato, Manabu Takahashi, Satoru Kawasaki, Katsuhiko Kaneko

  Environmental Geotechnics 2 (2) 104 - 117 2014/03 [Refereed][Not invited]
  
• Electrokinetic properties of pasteurii and aquimarina bacteria

  Hamed A. Keykha, Bujang B. K. Huat, Afshin Asadi, Mohsen Zareian, Satoru Kawasaki

  Environmental Geotechnics 2 (3) 181 - 188 2014/03 [Refereed][Not invited]
  
• Electrical disintegration and micro-focus X-ray CT observations of cement paste samples with dispersed mineral particles

  Sang Ho Cho, Mitsuhiro Yokota, Mayumi Ito, Satoru Kawasaki, Soo Bok Jeong, Byoung Kon Kim, Katsuhiko Kaneko

  MINERALS ENGINEERING 57 79 - 85 0892-6875 2014/03 [Refereed][Not invited]
   

  Electrical disintegration is an effective liberation technique in mineral processing where the liberation ratio depends on the mineralogical properties of the mineral grains. However elucidation of the liberation behavior is difficult since the fragments after the electrical disintegration are fine and complex. This study applies electrical disintegration to cement paste samples with various dispersed mineral particles (calcite, quartz, albite, and pyrite) and the disintegrated products are observed with a micro-focus X-ray CT scanner. Current channels and crack extension behavior from the channels are identified by cross sectional CT and three dimensional reconstructed images. A classification of the crack patterns was carried out and compared with the results of liberation ratio measurements of the products. (C) 2014 Elsevier Ltd. All rights reserved.
• Formation Mechanisms of Beachrocks in Okinawa and Ishikawa, Japan, with a Focus on Cements

  Takashi Danjo, Satoru Kawasaki

  MATERIALS TRANSACTIONS 55 (3) 493 - 500 1345-9678 2014/03 [Refereed][Not invited]
   

  Beachrock is a type of sedimentary deposit held together mainly by calcium carbonate cement in the tidal zone of sandy beaches in tropical and subtropical regions. Man-made beachrock has the potential to inhibit coastal erosion; considering this important application, we performed field investigations and laboratory tests to understand the formation mechanisms of beachrocks in Okinawa and Ishikawa, Japan. We performed a needle penetration test, microbial population count and urease activity test, and conducted elemental and mineral analyses. Our investigation showed that in Okinawa the evaporation of seawater and/or urease activity of the microorganisms may have resulted in precipitation of high Mg calcite, leading to the formation of beachrock. In Ishikawa, beachrock and sand were present near a spring with a relatively high concentration of Al3+. The mixing of spring water (pH 4.7) with seawater could have led to the precipitation of the Al- and Si-bearing cement that is consolidating the sand particles, leading to development of beachrock.
• Geological Exploration of Beachrock through Geophysical Surveying on Yagaji Island, Okinawa, Japan

  Ryosuke Kubo, Satoru Kawasaki, Koichi Suzuki, Shinji Yamaguchi, Toshiro Hata

  MATERIALS TRANSACTIONS 55 (2) 342 - 350 1345-9678 2014/02 [Refereed][Not invited]
   

  This paper describes the knowledge obtained from a study of geophysical prospecting for beachrock. Previous studies on beachrock worldwide have been focused on the geochemistry. However, more knowledge of the chemical and physical properties is needed to elucidate the formation mechanism. In the present study, a direct current (DC) electrical survey and a surface seismic survey were conducted to detect the underground structure of the beachrock on Yagaji Island, Okinawa, Japan. This was a first attempt at conducting multiple geophysical surveys to investigate beachrock. In each survey, one survey line was set perpendicular to the seashore and two survey lines were set roughly parallel to the seashore. The results of each survey were observed in section of resistivity and seismic wave velocity. Furthermore, in order to estimate the effectiveness of the surveys, laboratory tests were conducted on the beachrock samples collected from the study site to measure the porosity, the resistivity, and the velocities of primary- (P-) waves and secondary- (S-) waves. There was a superior correlation between the sections and with the data on the study site. Hence, the features of the beachrock at the site are as follows: the resistivity is about 4-16 Omega m, the S-wave velocity is about 325 m/s, the thickness is about 1 m, and the thickness has a tendency to become greater toward the sea. One beachrock formation mechanism obtained by this study is close a currently accepted mechanism.
• Characteristics of Beachrocks: A Review

  Takashi Danjo, Satoru Kawasaki

  Geotechnical and Geological Engineering 32 (2) 215 - 246 0960-3182 2014 [Refereed][Not invited]
   

  Beachrocks are calcareous rocks that have been quite recently formed and are found in the intertidal zone on sandy beaches. The authors are developing an artificial rock with self-healing capabilities that can be used in coastal areas to repair the infrastructure of coastal walls. Because beachrocks are formed naturally on beaches, they merit study as a model for artificial rocks. We conducted a bibliographical study in order to gather information about the characteristics of beachrocks, which may aid in the manufacturing of artificial rocks. This study investigated their geographic distribution, formative periods, physical properties, and origins. The study found that over 90 % of beachrocks are found between the latitudes 40°N and the Tropic of Capricorn, and that their formative periods range from 26,000 years to just a few decades ago. We also learned that the cement component of beachrocks mainly consists of either calcium carbonate or silica. The dynamic characteristics of these components have been studied in only three papers, which note that their uniaxial compression strength ranges from as low as 6.0 to 42.0 MPa. Since very limited data are available on beachrocks in Japan where the artificial rock technology will first be deployed, there is a need for collecting additional data on their mechanical properties, elemental composition ratios, and mineral content. © 2013 Springer Science+Business Media Dordrecht.
• Formation mechanisms of beachrocks in okinawa and Ishikawa, Japan, with a focus on cements

  Takashi Danjo, Satoru Kawasaki

  Materials Transactions 55 (3) 493 - 500 1345-9678 2014 [Refereed][Not invited]
   

  Beachrock is a type of sedimentary deposit held together mainly by calcium carbonate cement in the tidal zone of sandy beaches in tropical and subtropical regions. Man-made beachrock has the potential to inhibit coastal erosion considering this important application, we performed field investigations and laboratory tests to understand the formation mechanisms of beachrocks in Okinawa and Ishikawa, Japan.We performed a needle penetration test, microbial population count and urease activity test, and conducted elemental and mineral analyses. Our investigation showed that in Okinawa the evaporation of seawater and/or urease activity of the microorganisms may have resulted in precipitation of high Mg calcite, leading to the formation of beachrock. In Ishikawa, beachrock and sand were present near a spring with a relatively high concentration of Al3+. The mixing of spring water (pH 4.7) with seawater could have led to the precipitation of the Al- and Si-bearing cement that is consolidating the sand particles, leading to development of beachrock. © 2014 The Japan Institute of Metals and Materials.
• Soil reinforcement using calcium phosphate compounds

  Kawasaki, S, Akiyama, M

  Proceedings of International Conference on Georesources and Geological Engineering 412 - 421 2013/12 [Refereed][Invited]
  
• Enhancement of unconfined compressive strength of sand test pieces cemented with calcium phosphate compound by addition of various powders

  S. Kawasaki, M. Akiyama

  SOILS AND FOUNDATIONS 53 (6) 966 - 976 0038-0806 2013/12 [Refereed][Not invited]
   

  To improve the unconfined compressive strength (UCS) of a novel chemical grout composed of a calcium phosphate compound (CPC-Chem), we performed UCS tests and scanning electron microscopy (SEM) observations on sand test pieces cemented with CPC-Chem and four kinds of powders (tricalcium phosphate, TCP; magnesium phosphate. MgP, calcium carbonate, CC and magnesium carbonate. MgC) as seed crystals. The UCS of the CPC-Chem test pieces cemented with TCP and CC was significantly greater than that of the test pieces with no added powders. The UCS of the test pieces with TCP and CC additives exceeded the targeted value of 100 kPa and increased to a maximum of 261.4 kPa and 209.7 kPa for the test pieces with TCP and CC additives, respectively. Furthermore, the UCS of test pieces with 1 wt% or 5 wt% TCP and 1 wt% CC additives was maintained at a level exceeding 200 kPa for 168 days. SEM observations revealed net-like and three-dimensional structures in segments of test pieces cemented with 1 wt% or 5 wt % TCP and 1 wt% CC in CPC-Chem, which could have been the reason of the long-term stability of UCS (over 200 kPa for 168 days) observed in this study. These results suggest that the addition of TCP and CC significantly enhances the ground improvement afforded by CPC-Chem. (C) 2013 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.
• Geological structure of beachrock by geophysical exploration: applicayio to Yagaji Island in Okinawa, Japan

  Kubo, R, Kawasaki, S, Suzuki, K, Yamaguchi, S, Hata, T

  Proceedings of the 11th Society of Exploration Geophysics of Japan International Symposium Paper ID: 051  2013/11 [Refereed][Not invited]
  
• A study of the formation mechanism of beachrock in Okinawa, Japan: Toward making artificial rock

  Danjo, T, Kawasaki, S

  Proceedings of the Third International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2013) 101 - 106 2013/11 [Refereed][Not invited]
  
• Effect of Addition of Phosphate Powder on Unconfined Compressive Strength of Sand Cemented with Calcium Phosphate Compound

  Satoru Kawasaki, Masaru Akiyama

  MATERIALS TRANSACTIONS 54 (11) 2079 - 2084 1345-9678 2013/11 [Refereed][Not invited]
   

  For the purpose of improving a novel grout composed of a calcium phosphate compound (CPC-Chem), we have conducted an unconfined compressive strength (UCS) test on samples cemented with CPC-Chem and tricalcium phosphate (TCP) powder. The UCS of these test samples was significantly larger than the UCS of the non-additive test samples. The UCS reached the targeted value of over 100 kPa, and after 28 days of curing, reached a maximum of 261.4 kPa. Additionally, the pH of the samples cemented with CPC-Chem and TCP powder was weakly acidic. These results suggest that the novel geotechnical method using a combination of CPC-Chem and TCP powder has the potential to be used as a non-contaminating and recyclable application, as a biogrout that uses microbial activity and for ground improvement because it satisfies the strength requirements for practical use.
• Geological structure of beachrock using electrical resistivety and surface wave - Application to the coastal area at Yagaji island in Nago-shi, Okinawa -

  Suzuki, K, Kawasaki, S, Kubo, R, Yamaguchi, S, Hata, T

  BUTSURI-TANSA Geophysical Exploration 社団法人 物理探査学会 66 (4) 277 - 285 0912-7984 2013/10 [Refereed][Not invited]
   

  Previous studies of artificial bedrock with self-repair ability in coastal area have indicated the important of building coastal levees at low cost with minimal environment load. The goal is to form the extreme artificial bedrock using natural materials (e.g., microbes, sand, shell, pieces of coral, and seaweed etc.) in a short time that can tolerate climate conditions. Most studies have focused on beachrocks in tropical and subtropical coral reef coastal areas, but little research has been done on the subsurface structure. Therefore, we performed both a DC electrical survey and a surface wave survey along the same lines to elucidate the subsurface structure of beachrocks in the coastal area of Okinawa Prefecture, Japan. In addition, we measured the physical properties of the beachrock sample collected from the survey lines by laboratory tests. As the results, both the resistivity and the shear wave velocity of the beachrock were higher than those of the underlying unconsolidated sand layer. Furthermore, the beachrock is up to approximately 1 m thick, increasing toward the coastline.
• Estimation of regional stress state and Young's modulus by back analysis of mining-induced deformation

  J. Kodama, T. Miyamoto, S. Kawasaki, Y. Fujii, K. Kaneko, P. Hagan

  INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES 63 1 - 11 1365-1609 2013/10 [Refereed][Not invited]
   

  A method to evaluate regional stress state and Young's modulus by analyzing the mining-induced deformation of ground is proposed. The effect of changes in regional strain state due to tectonic plate motion can be accounted for using the proposed method. Mining-induced deformation can manifest itself as changes in ground surface geometry resulting from mining activity. There are three underlying factors that can contribute to the deformation, these being: displacement induced by the effect of gravity; displacement induced by the effect of horizontal regional strain; and, incremental change in the horizontal regional strain. Both regional strain and Young's modulus can be simultaneously estimated, because the displacement induced by the regional strain is independent of the Young's modulus and the displacement induced by the gravity is inversely proportional to the Young's modulus. The relative displacement arising from the mining excavation at the Torigatayama limestone mine in Japan has been measured by GPS. Both the regional stress state and Young's modulus were estimated by back analysis of the relative displacement using a 3-D finite element method. It was shown that back analysis based on changes in distance between the measurement points provides a more reliable estimation than that could be achieved based on the direct relative displacement. (C) 2013 Elsevier Ltd. All rights reserved.
• Beachrock mapping by geophysical exploration: Application to Yagaji Island in Okinawa, Japan

  Kubo, R, Kawasaki, S, Suzuki, K, Yamaguchi, S, Hata, T

  Proceedings of EUROCK 2013 - The ISRM International Symposium, Rock Mechanics for Resources, Energy and Environment 299 - 304 2013/09 [Refereed][Not invited]
  
• A study of the formation mechanism of beachrock in Okinawa, Japan: toward making artificial rock

  Danjo, T, Kawasaki, S

  International Journal of GEOMATE The GEOMATE International Society 5 (1) 634 - 639 2186-2982 2013/09 [Refereed][Not invited]
  
• Formation mechanisms of beachrocks based on cement materials

  Danjo, T, Kawasaki, S

  Journal of the Mining and Materials Processing Institute of Japan The Mining and Materials Processing Institute of Japan 129 (7) 520 - 528 1881-6118 2013/07 [Refereed][Not invited]
   

  Beachrocks are coastal deposits cemented mainly by calcium carbonate cement; these deposits are found in the tidal zone of sandy beaches in tropical and subtropical regions. Manmade beachrocks have the potential to inhibit coastal erosions; considering this important application, we performed field investigations and laboratory tests to understand the formation mechanisms of beachrocks in Okinawa and Ishikawa, Japan. We performed a needle penetration test, determination of viable count, elemental analyses and mineral analysis. Our investigation of the formation mechanisms of the beachrocks showed that in Okinawa, the evaporation of seawater and/or urease activity of the microorganisms may have resulted in the precipitation of high Mg calcite (HMC), leading to the formation of beachrocks. On the other hand, in Ishikawa, beachrocks and sand were present near a spring. Here, the pH value of the spring was in the range 4.7 and it has a higher concentration of Al³⁺. The mixing of spring water with seawater could have led to the precipitation of the cement containing Al and Si between sand particles and, thus resulting in the formation of the beachrock. Therefore, we have interpreted the formation mechanisms of beachrocks.
• Geological structure of beachrock using electrical resistivity and surface wave surveys Application to the coastal area at Yagaji island in Nago-shi, Okinawa

  SUZUKI Koichi, KAWASAKI Satoru, KUBO Ryosuke, YAMAGUCHI Shinji, HATA Toshiro

  物理探査学会学術講演会講演論文集 = Proceeding of the SEGJ Conference 物理探査学会 128 150 - 153 2013/06/13 [Not refereed][Not invited]
  
• Unique grout material composed of calcium phosphate compounds

  Kawasaki, S, Akiyama, M

  International Journal of GEOMATE The GEOMATE International Society 4 (1) 429 - 435 2186-2982 2013/03 [Refereed][Not invited]
  
• Evaluation of Porosity and Its Variation in Porous Materials Using Microfocus X-ray Computed Tomography Considering the Partial Volume Effect

  Masaji Kato, Manabu Takahashi, Satoru Kawasaki, Toshifumi Mukunoki, Katsuhiko Kaneko

  MATERIALS TRANSACTIONS 54 (9) 1678 - 1685 1345-9678 2013 [Refereed][Not invited]
   

  The physical properties of two-phase materials depend on their internal structure. Therefore, segmentation of the structure of such materials is important in material sciences. In this study, we used a maximum likelihood thresholding method that considered the partial volume effect -i.e., the effect of mixels (mixed pixels)- to calculate the porosities of packed glass beads and the Berea sandstone using microfocus X-ray computed tomography (CT) images. We also examined the effects of scanning conditions on the segmentation results and assessed the porosity of possible packing structures of the glass beads to be segmented to be 33-37% based on histogram data. Moreover, we evaluated the porosity of the Berea sandstone to be 18%. Then, we examined variation in the porosity of biogrouted packing of glass beads using a microfocus X-ray CT scanner and histogram-based image analysis with the same thresholding method. Our results indicated that the ratio of grouted to ungrouted geomaterial porosities was 0.98, whereas the value estimated by measuring changes in the concentration of calcium ions was 0.98-0.99. Thus, we have confirmed that the proposed method can evaluate small changes in porosity with high accuracy.
• Influencing factors of strength increase of beachrocks

  Danjo, T, Kawasaki, S

  Proceedings of the 13th Japan Symposium on Rock Mechanics & the 6th Japan-Korea Joint Symposium 617 - 622 2013/01 [Not refereed][Not invited]
  
• Unique grouting material composed of calcium phosphate compounds

  Kawasaki, S, Akiyama, M

  Proceedings of the Second International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2012) 40 - 46 2012/11 [Not refereed][Invited]
  
• Electrophoresis of bacteria and electro-biogrouting

  Hamed A. Keykha, Bujang B. K. Huat, Afshin Asadi, S. Kawasaki

  Proceedings of the Second International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2012) 230 - 233 2012/11 [Not refereed][Not invited]
  
• Physical and mechanical properties of beachrocks in Okinawa Island

  Danjo, T, Kawasaki, S

  Journa of Japan Society of Engineering Geology 一般社団法人 日本応用地質学会 53 (4) 191 - 200 0286-7737 2012/10 [Refereed][Not invited]
   

  There are very few reports about physical and mechanical properties of beachrocks in the world. To obtain the properties of beachrocks and to investigate their correlations between unconfined compression strength and other properties such as density, water content, etc., we performed a series of in-situ tests and laboratory tests for beachrocks in Okinawa Island. As a result, it was shown that the average values of unconfined compression strengths of the beachrock samples obtained from three testing sites were 11.14MPa, 19.91MPa and 42.23MPa, respectively. It was also understood that density and unconfined compression strength of the beachrocks increased along with the passage of time while water content decreased. Moreover, it was found that there was a relationship like qu = 0.00000654 t2+0.0101 t between unconfined compression strength, qu (MPa), and calibrated radiocarbon age, t(y Cal BP).
• Improvement in the unconfined compressive strength of sand test pieces cemented with calcium phosphate compound by addition of calcium carbonate

  Masaru Akiyama, Satoru Kawasaki

  ECOLOGICAL ENGINEERING 47 264 - 267 0925-8574 2012/10 [Refereed][Not invited]
   

  We added calcium carbonate (CC) powder to a novel grout made from calcium phosphate compound (CPC-chem) to increase the ground strength improvement afforded by CPC-chem. We conducted the unconfined compressive strength (UCS) test and scanning electron microscopy (SEM) observation on test pieces cemented with CPC-chem and CC powder. The UCS of test pieces cemented with CPC-chem and CC powder was significantly higher than that of test pieces cemented without CC powder, and it reached a maximum of 209.7 kPa. The UCS of test pieces cemented with CC powder and deionized water was 12.5 kPa, which was similar to that of test pieces cemented with deionized water only (10 kPa). SEM observation revealed mesh-like and three-dimensional structures in the segment of the test piece cemented with CPC-chem and 1 wt% of CC, which showed UCS of over 200 kPa and the minimum axial strain rate among all cases in this study. These results suggest that the addition of CC powder significantly enhances the ground improvement afforded by CPC-chem. (c) 2012 Elsevier B.V. All rights reserved.
• Effect of the addition of various powders on unconfined compressive strength of cemented sand with calcium phosphate compound

  Akiyama, M, Kawasaki, S

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 7 (3) 491 - 501 1880-6341 2012/09 [Refereed][Not invited]
  
• Segmentation of multi-phase X-ray computed tomography images of porous materials considering partial volume effect

  Kato, M, Yamanaka, H, Takahashi, M, Kawasaki, S, Kaneko, K

  Proceedings of the 2012 World Congress on Advances in Civil, Environmental, and Materials Research (ACEM' 12) 278 - 294 2012/08 [Not refereed][Not invited]
  
• Characteristcs of beachrock based on bibliographocal research: Toward the development of man-made beachrock

  Danjo, T, Kawasaki, S

  Journal of Japan Society of Engineering Geology 日本応用地質学会 53 (3) 129 - 141 0286-7737 2012/08 [Refereed][Not invited]
  
• Properties of beachrocks in Okinawa and Ishikawa, Japan

  Danjo, T, Kawasaki, S

  Proceedings of the 34th International Geological Congress 1521  2012/08 [Not refereed][Not invited]
  
• Microbially mediated sand solidification using calcium phosphate compounds

  Masaru Akiyama, Satoru Kawasaki

  ENGINEERING GEOLOGY 137 29 - 39 0013-7952 2012/06 [Refereed][Not invited]
   

  To evaluate the potential utility of a new calcium-phosphate-compound (CPC)-based biogrout (CPC biogrout), we conducted unconfined compressive strength (UCS) tests and scanning electron microscope (SEM) observations of sand test pieces cemented with CPC biogrout. The CPC biogrout was produced using (1) soil extracts that contained microorganisms derived from one of two soils, which had different pH values, and (2) one of three amino acids or urea as a pH-increasing reactant. A temporal increase in pH was observed in slightly acidic soil by the addition of ammonia sources. On the other hand, there was no significant increase in pH in slightly alkaline soil except for that due to urea. In most cases, the UCS of the test pieces cemented with CPC biogrout produced using soil extracts from acidic soil along with an ammonia source was higher than that of the test pieces cemented with CPC biogrout produced without the addition of ammonia sources. SEM observation of test pieces with UCS of over 50 kPa showed the presence of whisker-like CPC crystals. These results suggest that CPC biogrout affords sufficient strength as a countermeasure for soil liquefaction and that amino acids can be used as new pH-increasing reactants for CPC biogrout In addition, they suggest that either CPC biogrout or CPC chemical grout alone, or a combination of the two grouts, can be used depending on the various properties of grounds and soils. (C) 2012 Elsevier B.V. All rights reserved.
• Electro-Biogrouting and Its Challenges

  Hamed A. Keykha, Bujang B. K. Huat, Afshin Asadi, Satoru Kawasaki

  INTERNATIONAL JOURNAL OF ELECTROCHEMICAL SCIENCE 7 (2) 1196 - 1204 1452-3981 2012/02 [Refereed][Not invited]
   

  Biogrouting is a new method to stabilize sandy soils through precipitation of CaCO3 between grains. This process decreases the permeability about 98% and increases the soil strength up to 12Mpa. It is created by bacterium Bacillus Pasteurii and enzyme urease that hydrolyze urea to carbonic dioxide and ammonia. A major problem in biogrouting is the distribution of bacteria injected into the soils. The bacteria grows more in at 30-37 degrees C and pH 9.2, but cannot be distributed homogeneously in soil through biogrouting technique. It depends on the grain size, mineralogy, and properties of the pore fluid. The electrokinetic (EK) technique transports charged particles and fluid in porous media. This technology moves a wide range of particles, including ions, metals and organics. The Bacillus bacteria are rod-shaped bacterium with many negative charges in the surface. The electrokinetic can probably transport bacteria towards the cathode in an experimental cell and can distribute them uniformly in porous media of soils for fertile biogrouting. It explains a wide range of diffusion of bacteria influenced electric current. However, basic environment electrokinentic phenomena can probably affect bacterial membrane composition and metabolic activity, but it also justifies an increase of soil pH and can provide a positive effect on microbial activity and bacterial community of Bacillus Pasteurii. Furthermore distribution of the urease enzyme could be possible in electrokinetic environment since the urease enzyme has a negative charge at pH of more than 5.5. The urease enzyme is a negatively charged at a pH more than 5.5 which is able to move and diffuse in electrical environment.
• Experimental study of the calcite precipitation based on the urease production bacterium isolated from peat

  Hata, T, Sato, A, Kawasaki, S, Abe, H

  Journal of Japan Society of Civil Engineers, Ser.C (Geosphere Engineering) 68 (1) 31 - 40 2012 [Refereed][Not invited]
  
• Physical and mechanical properties of beachrock

  Danjo, T, Kawasaki, S

  Proceedings of the 41st Symposium on Rock Mechanics 89 - 94 2012 [Not refereed][Not invited]
  
• Novel grout material comprised of calcium phosphate compounds: In vitro evaluation of crystal precipitation and strength reinforcement

  Masaru Akiyama, Satoru Kawasaki

  ENGINEERING GEOLOGY 125 119 - 128 0013-7952 2012/01 [Refereed][Not invited]
   

  Calcium phosphate compounds (CPCs) have unique physicochemical properties. As grout material, they afford many advantages such as adequate physical strength, self-setting property, pH dependence of precipitation, non-toxicity, and recyclability. To apply CPCs to the permeability control and reinforcement of ground soil and rock, we explored suitable conditions for in vitro CPC precipitation, conducted unconfined compressive strength (UCS) tests of Toyoura sand test pieces cemented by CPC, and carried out observations and elemental analysis of precipitated CPC crystals. Two kinds of phosphate stock solution and two kinds of calcium stock solution were used to prepare the reaction mixtures, and CPC precipitation was detected in all reaction mixtures. The volume of CPC precipitation in the reaction mixture increased as the pH rose from strongly acidic to around neutral. The UCS of Toyoura sand test pieces cemented by 1.5 M diammonium phosphate and 0.75 M calcium acetate tended to increase with time, reaching a maximum of 63.5 kPa after 14 days of curing. Conversely, the UCS of test pieces cemented by using calcium nitrate was below 20 kPa and showed no significant increase in strength. CPC precipitation with calcium nitrate induced the formation of plate-like crystals, whereas that with calcium acetate induced whisker-like crystals. Elemental analysis of the cemented test pieces showed that the distributions of phosphorus and calcium were similar. The results indicate the practical feasibility of using novel CPC grouts as chemical grouts because of their self-setting property, and as biogrouts because of their crystal structure and pH dependence of precipitation. (C) 2011 Elsevier B.V. All rights reserved.
• New grouting materials using calcium phosphate compounds

  M. Akiyama, S. Kawasaki

  HARMONISING ROCK ENGINEERING AND THE ENVIRONMENT 1449 - 1452 2012 [Not refereed][Not invited]
   

  To develop novel rock grout materials using Calcium Phosphate Compounds (CPC), we explored suitable conditions for CPC precipitation in vitro, conducted Unconfined Compressive Strength (UCS) tests of sand test pieces cemented by CPC, and observed precipitated CPC crystals by scanning electron microscopy. The volume of CPC precipitation in the reaction mixture increased with pH, rising from weakly acidic to around neutrality. Sand test pieces cemented with a reaction mixture containing 1.5M diammonium phosphate and 0.75M calcium acetate showed a tendency for the UCS to increase with time, reaching a maximum of 87.6 kPa. CPC precipitation via calcium nitrate treatment induced the formation of platelike crystals, whereas that via calcium acetate treatment induced whisker-like crystals. The results indicate the fundamental feasibility of novel CPC rock grouts including chemical grouts using the self-setting property of CPC, and biogrouts using the pH dependence of the precipitation and crystal structure of CPC.
• Property evaluation of beachrock based on field investigation in Okinawa Island, Japan

  T. Danjo, S. Kawasaki

  HARMONISING ROCK ENGINEERING AND THE ENVIRONMENT 949 - 952 2012 [Not refereed][Not invited]
   

  Beachrock is a coastal deposit with calcium carbonate and/or silica cement in the tidal zone of sandy beaches. Considering the application of man-made beachrock to preserve submerged-looking islands, we performed a literature survey and a field investigation to understand essential beachrock characteristics. We found that 90% of beachrocks worldwide were distributed within latitude of approximately 40 degrees north of the southern circle. It was also found that beachrock formed from several decades ago to around 7350 years ago. Furthermore, the main elements in beachrock worldwide differed. The beachrock in Okinawa, Japan mainly consisted of Ca and C. The unconfined compression strength, q(u), was from 5.63 to 57.80MPa. The relation between qu and formative age, t, was q(u) = 0.0141t. From these results, we obtained a wealth of data to build man-made beachrock.
• Fundamental study on new grouting material using calcium phosphate compounds: Effect of addition of ammonia sources and soil microorganisms on unconfined compression strength

  Akiyama, M, Kawasaki, S, Aoi, S

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 6 (4) 513 - 524 1880-6341 2011 [Refereed][Not invited]
  
• Ground improvement technologies using microbial functions

  Kawasaki, S

  Ground Engineering 29 (1) 11 - 18 2011 [Refereed][Invited]
  
• Relationship between crystal features of calcium phosphate compounds in chemical grout and unconfined compression strength of grouted sand

  Aoi, S, Kawasaki, S, Akiyama, M

  Proceedings of International Conference "Environmental Geosciences and Engineering Survey for Territory Protection and Population Safety" 504 - 508 2011 [Not refereed][Not invited]
  
• Fundamental study on new grouting material using calcium phosphate compounds: Crystal precipitation test and unconfined compression test of sand test pieces

  Akiyama, M, Kawasaki, S

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 6 (2) 341 - 350 1880-6341 2011 [Refereed][Not invited]
  
• Segmentation of internal structure of two-phase materials using micro-focus X-ray CT,

  Yamanaka, H, Kawasaki, S, Kato, M, Mukunoki, T, Kaneko, K

  Jaban Kogaku Janaru (Japanese Geotechnical Journal) 6 (2) 273 - 284 1880-6341 2011 [Refereed][Not invited]
  
• A centrifugal model test of microbial carbonate precipitation as liquefaction countermeasure

  Inagaki, Y., Tsukamoto, M., Mori, H., Nakajima, S., Sasaki, T., Kawasaki, S.

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 6 (2) 157 - 167 1880-6341 2011 [Refereed][Not invited]
  
• Basic study on development of bio-cover soil applying microbial metabolism

  Mukunoki, T, Kawasaki, S, Shimoyashiki, A, Yoshinaga, T

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 5 (4) 545 - 553 1880-6341 2010 [Refereed][Not invited]
  
• Examination of applicability of injection pipe that uses biodegradable plastic in the ground improvement

  Terajima, R, Shimada, S, Oyama, T, Kawasaki, S

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 5 (3) 425 - 435 1880-6341 2010 [Refereed][Not invited]
  
• Estimation of regional stress state and Young's modulus by analyzing mining induced deformation

  E. Nishiyama, T. Miyamoto, J. Kodama, S. Kawasaki, K. Kaneko, Y. Yoshida

  ROCK MECHANICS IN CIVIL AND ENVIRONMENTAL ENGINEERING 681 - 684 2010 [Not refereed][Not invited]
   

  A method to evaluate regional stress state and Young's modulus by analyzing mining induced deformation of ground is proposed. Mining induced deformation is interpreted as the deformation due to the geometrical change of ground surface caused by mine activity and it is classified into two types, i.e., the displacement increment induced by the gravity and that by the horizontal regional strain. It is pointed out that both regional strain and Young's modulus can be estimated by analyzing the mining induced deformation, because the displacement induced by the regional strain is independent of the Young's modulus and the displacement induced by the gravity is in inversely proportional to the Young's modulus. The relative displacement arising from mine excavation in Torigatayama limestone mine, Japan have been measured by GPS. Both the stress state and Young's modulus of the regional field including the limestone mine were estimated by back-analysis using three dimensional finite element method. It is shown that the maximum principal direction of the regional stress is almost NE-SW and Young's modulus of the ground is between 3 and 6 GPa.
• Effect of temperature on precipitation of calcium carbonate using soil microorganisms

  Kawasaki, S, Ogata, S, Hiroyoshi, N, Tsunekawa, M, Kaneko, K, Terajima, R

  Journal of Japan Society of Engineering Geology 一般社団法人 日本応用地質学会 51 (1) 10 - 18 0286-7737 2010 [Refereed][Not invited]
   

  We have been performing fundamental laboratory tests in order to develop a novel conceptual grout, hereafter called biogrout. Hardened biogrout consists primarily of calcium carbonate or silica, typical cement elements in soil and rock. These compounds can fill the voids and cracks in soil and rock using microbial metabolism. This paper reports some test results for biogrout using calcium carbonate and discusses them. We performed a series of precipitation tests on calcium carbonate in test tubes using soil microorganisms sampled from various parts of Japan, examining the effect of temperature on the precipitation of calcium carbonate when testing. As a result, it was indicated that precipitation of calcium carbonate using soil microorganisms occurred at temperatures ranging from 5 to 35°C. Furthermore, we measured the number of soil microorganisms used in the tests and conducted gene analyses of them. The phases of soil microorganisms before testing were compared to those after testing by determining the number of living soil microorganisms, the highest relative frequency of soil microorganisms, and their attributive taxonomical groups. In consequence, it is possible that fungi such as the Penicillium and Aspergillus species frequently metabolized organic nutrition, and at the same time their number increased via their metabolism.
• Study on impact assessment of pH and organic nutrient source in solvents for production of bio-cover soil due to microbial metabolism

  Mukunoki, T, Yoshinaga, T, Kawasaki, S

  Jiban Kogaku Janaru (Japanese Geotechnical Journal) 5 (1) 69 - 80 1880-6341 2010 [Refereed][Not invited]
  
• Evaluation of porosity in geomaterials treated with biogrout considering partial volume effect

  Kobayashi, Y, Kawasaki, S, Kato, M, Mukunoki, T, Kaneko, K

  Proceedings of the 3rd International Workshop on X-Ray CT for Geomaterials: GeoX 2010 287 - 294 2010 [Refereed][Not invited]
  
• X線CT法によるバイオグラウト処理された供試体内部の間隙率評価

  小林優矢, 川﨑 了, 加藤昌治, 椋木俊文, 金子勝比古

  第39回岩盤力学に関するシンポジウム講演集 213 - 217 2010 [Not refereed][Not invited]
  
• Applicability of a method for evaluation of porosity to biogrouted geomaterials

  Kobayashi, Y, Kawasaki, S, Kato, M, Mukunoki, T, Kaneko, K

  Journal of the Mining and Materials Processing Institute of Japan The Mining and Materials Processing Institute of Japan 125 (10/11) 540 - 546 1881-6118 2009 [Refereed][Not invited]
   

  This study considers a method for evaluation of porosity of biogrouted geomaterials. First, we visualized the internal structures of the specimens by using micro-focused X-ray CT scanner. We tested Souma sand, gum tips, plastic pellets, steel balls and glass beads as geomaterial to find suitable geomaterials for evaluation of porosity: geomaterials whose CT-number histogram was bimodal. The results clarified that one of the geomaterials, glass beads whose particle size was 0.50-0.71mm, was suitable for evaluation of porosity. Second, we calculated the porosity of the glass beads by using a method for evaluation of porosity based on a maximum likelihood thresholding method considering the effect of mixels. The result showed that the ratio of the porosity of grouted geomaterial to that of ungrouted geomaterial was 0.98 to 0.99. On the other hand, the value estimated by the measurement of changes in concentration of calcium ion was 0.98. Thus, both values closely agreed. Therefore, this study clarifies that the method enables us to evaluate small change in porosity with great accuracy.
• Temperature dependence of calcium carbonate precipitation for biogrout

  Ogata, S, Kawasaki, S, Hiroyoshi, N, Tsunekawa, M, Kaneko, K, Terajima, R

  Proceedings of the Regional Symposium of the International Society for Rock Mechanics, EUROCK 2009 339 - 344 2009 [Not refereed][Not invited]
  
• Solidification of dredged clayey soil from farm ponds based on biochemical grouting

  Kiyota, K, Murakami, A, Kawasaki, S

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 50 (2) 70 - 78 0286-7737 2009 [Refereed][Not invited]
   

  Soils dredged from the farm ponds to improve the water quality and the efficiency of storage of reservoirs cannot easily be dealt with or transferred to be reused because of high water content. In this paper, a series of laboratory experiments is carried out to examine a solidification procedure of such soil based on the biochemical grouting technique, e.g., the biogrout, instead of existing procedure using chemical solidification mixture which fills the fissure and the pore in soil using microorganic metabolism with colloidal silica. It is revealed from the test tube experiments that a set of 5ml of colloidal Silica, 1.25g of yeast and 0.3g of glucose is effective in dealing with 5g of dredged soil. Existing microorganism and organic nourishment source nutrition involved dredged soil is applicable to the biochemical reaction through the examination of the compounding ratio of the biochemical grout to the dredged soil, and the amount of dredged soil to be necessary for solidification within the biochemical grout processing. It is also found that the biogrout declines the plastic index of dredged soil and solidify the soil by comparing the penetration of the fall cone test before and after the biochemical grout processing under the same water contents.
• Effect of temperature on rate of CaCO₃ precipitation for biogrouting process

  Ogata, S, Kawasaki, S, Hiroyoshi, N, Tsunekawa, M, Kaneko, K, Terajima, R

  Proceedings of 3rd International Workshop and Conference on Earth Resources Technology 12 - 17 2009 [Refereed][Not invited]
  
• Fundamental study of siliceous biogrout for eco-friendly soil improvement

  Terajima, R, Shimada, S, Oyama, T, Kawasaki, S

  Journal of Geotechnical Engineering, Japan Society of Civil Engineers, C 65 (1) 120 - 130 1880-604X 2009 [Refereed][Not invited]
  
• 微生物代謝を利用したグラウトにおける炭酸カルシウム析出の温度依存性

  小潟 暁, 川﨑 了, 広吉直樹, 恒川昌美, 金子勝比古, 寺島 麗

  第38回岩盤力学に関するシンポジウム講演論文集 120 - 124 2009 [Not refereed][Not invited]
  
• Effect of temperature on precipitation of calcium carbonate for biogrout

  Ogata, S, Kawasaki, S, Hiroyoshi, N, Tsunekawa, M, Kaneko, K, Terajima, R

  Proceedings of the Korean Rock Mechanics Symposium 2008 -International Cooperation and Rock Engineering for Development of Mineral Resources and Infrastructures- 271 - 277 2008 [Not refereed][Not invited]
  
• Estimation of regional stress state and Young’s modulus by measurement of mining induced deformation

  Nishiyama, E, Miyamoto, T, Kodama, J, Kawasaki, S, Kaneko, K

  Journal of the Mining and Materials Processing Institute of Japan The Mining and Materials Processing Institute of Japan 124 (9) 570 - 575 1881-6118 2008 [Refereed][Not invited]
   

  A method to evaluate the regional stresses and the Young's modulus by analyzing mining induced deformation of the ground is proposed.
  Mining induced deformation is interpreted as the deformation due to the geometrical change of the ground surface caused by mine activity and it is classified in two types, i.e., the displacement increment induced by gravity and that by the horizontal regional strain. It is pointed out that both the regional strain and Young's modulus can be estimated by analyzing the mining induced deformation, because the displacement induced by the regional strain is independent of the Young's modulus and the displacement induced by the gravity is inversely proportional to the Young's modulus.
  The relative displacement due to mine excavation in Torigatayama mine were measured by GPS (Global Positioning System) and the regional stress state and Young's modulus were estimated by a back-analysis using three dimensional finite element method. It is shown that the maximum principal direction of regional stresses is almost NE-SW and Young's modulus of the ground is 3 to 6GPa in the present field.
• 鳥形山鉱山における広域応力と地盤ヤング率の検討

  西山えるむ, 宮本高充, 児玉淳一, 川﨑 了, 金子勝比古

  第12回岩の力学国内シンポジウム講演論文集 281 - 287 2008 [Not refereed][Not invited]
  
• 微生物代謝を用いたシリカ系注入材バイオグラウトの開発

  寺島 麗, 島田俊介, 小山忠雄, 市川智史, 川﨑 了, 広吉直樹

  第12回岩の力学国内シンポジウム講演論文集 239 - 244 2008 [Not refereed][Not invited]
  
• バイオグラウトにおける炭酸カルシウムの析出に及ぼす温度の影響

  川﨑 了, 小潟 暁, 広吉直樹, 恒川昌美, 金子勝比古, 寺島 麗

  地盤工学会北海道支部技術報告集 (48) 27 - 30 2008 [Not refereed][Not invited]
  
• Estimation of Weathering Thickness of Man-made Weathering Rocks with the Equotip Hardness Tester

  Satoru KAWASAKI, Sang Ho CHO, Katsuhiko KANEKO

  Journal of the Japan Society of Engineering Geology 一般社団法人日本応用地質学会 48 (4) 162 - 169 0286-7737 2007 [Not refereed][Not invited]
   

  In general, rocks are oxidized and weathered when they are exposed to the surface of the earth by natural erosions or man-made excavations. As a consequence, the strength of rocks that suffered such weathering decreases in the end. Provided that a new method which can estimate weathering thickness of rocks nondestructively, simply and quantitatively in the fields is developed, it is expected that the method is useful for the practical fields such as engineering geology, geotechnical engineering and so forth. In order to develop a new estimation method for weathering thickness of rocks like boring cores or relatively shallow weathering layers of outcropping rock masses, the authors produced four kinds of man-made weathering rocks modeled on natural weathering rocks. Then a series of Equotip rebound hardness tests was conducted by using man-made weathering rocks. Furthermore, an experimental investigation was carried out by taking notice of especially weathering thickness of man-made weathering rocks and the ratio of weathering layers to nonweathering layers in rebound hardness. In this paper, firstly the man-made weathering rock model by which weathering thickness of weathering rocks and shallow weathering layers of rock masses can be estimated is explained. Secondly, some investigation results of the method for producing weathering layers of man-made weathering rocks and homogeneity of produced weathering layers are reported. Lastly, a new method for estimating weathering thickness of man-made weathering rocks nondestructively, simply and quantitatively is suggested by using rebound hardness of man-made weathering rocks, weathering layers and nonweathering layers, respectively.
• Estimation of weathering thickness of man-made weathering rocks with the Equotip hardness tester

  Kawasaki, S, Cho, SH, Kaneko, K

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 48 (4) 162 - 169 0286-7737 2007 [Refereed][Not invited]
   

  In general, rocks are oxidized and weathered when they are exposed to the surface of the earth by natural erosions or man-made excavations. As a consequence, the strength of rocks that suffered such weathering decreases in the end. Provided that a new method which can estimate weathering thickness of rocks nondestructively, simply and quantitatively in the fields is developed, it is expected that the method is useful for the practical fields such as engineering geology, geotechnical engineering and so forth. In order to develop a new estimation method for weathering thickness of rocks like boring cores or relatively shallow weathering layers of outcropping rock masses, the authors produced four kinds of man-made weathering rocks modeled on natural weathering rocks. Then a series of Equotip rebound hardness tests was conducted by using man-made weathering rocks. Furthermore, an experimental investigation was carried out by taking notice of especially weathering thickness of man-made weathering rocks and the ratio of weathering layers to nonweathering layers in rebound hardness. In this paper, firstly the man-made weathering rock model by which weathering thickness of weathering rocks and shallow weathering layers of rock masses can be estimated is explained. Secondly, some investigation results of the method for producing weathering layers of man-made weathering rocks and homogeneity of produced weathering layers are reported. Lastly, a new method for estimating weathering thickness of man-made weathering rocks nondestructively, simply and quantitatively is suggested by using rebound hardness of man-made weathering rocks, weathering layers and nonweathering layers, respectively.
• The influence of rock texture on argillaceous rock heaving: A case of Notoro argillaceous rock

  Kashiwaya, K, Kawasaki, S, Kaneko, K, Yoneda, T

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 48 (2) 97 - 102 0286-7737 2007 [Refereed][Not invited]
   

  To clarify factors causing uneven heaving on a cutting plane of Tertiary Miocene Notoro formation, mineralogy, chemistry, and rock texture were examined. Samples are four argillaceous rocks collected from the cores of noticeably or slightly heaving points. Results showed that the samples of the noticeably and slightly heaving points have similar mineral and chemical compositions, but their rock textures are different. The samples of the noticeably heaving point have coarser granular variations than those of the slightly heaving point, and the matrix of the former was more widely impregnated with fluorescent resin than it of the latter. When it is assumed that the heaving occurred from the influence of water, the uneven heaving may result from difference in void structures which developed closely correlating with the granular variations.
• Fundamental study on novel grout cementing due to microbial metabolism

  Kawasaki, S, Murao, A, Hiroyoshi, N, Tsunekawa, M, Kaneko, K

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 47 (1) 2 - 12 0286-7737 2006 [Refereed][Not invited]
   

  Natural soil contains approximately 10^7 to 10^9 microorganisms per gram. Considering this large number of microorganisms, it is expected that soil and rock engineering, especially the field of mechanics, may be able to develop a novel eco-friendly technology to improve the scalability of soil and rock. We performed fundamental laboratory tests in order to develop a novel conceptual grout, hereafter denoted as biogrout. Biogrout consists primarily of calcium carbonate, one of the typical cement elements in soil and rock. This compound can fill the voids and cracks in soil and rock using microbial metabolism. We performed separation tests on calcium carbonate in test tubes, examining the effects of several test conditions, including temperature, organic nutrition, and different buffering conditions, on the separation of calcium carbonate when challenged with commercially available dry yeast and microorganisms naturally living in soil. Furthermore, we examined the improvements in the sealability of sand and clay following biogrout improvement, confirming that coefficients of permeability of both soil types decreased by approximately one order of magnitude from those seen for normal soils. Although a number of problems will need to be addressed, these test results indicate that biogrout is a promising candidate to improve ground properties. The development of such a compound has been successful using microbial metabolism.
• 微生物代謝により固化する新しいグラウトに関する基礎的検討

  村尾彰了, 川﨑 了, 広吉直樹, 恒川昌美, 金子勝比古

  第34回岩盤力学に関するシンポジウム講演論文集 417 - 422 2005 [Not refereed][Not invited]
  
• Effect of water content on optical and mechanical properties of rocks

  F Shiraki, S Kawasaki, K Kaneko

  Contribution of Rock Mechanics to the New Century, Vols 1 and 2 899 - 902 2004 [Not refereed][Not invited]
   

  Relationships between optical and mechanical properties of rocks are discussed by paying attention to brightness and brightness difference of rocks with change of water content. In order to investigate effect of water content on optical and mechanical properties of several rocks, a series of laboratory test was conducted. The obtained results show that brightness and brightness difference could be one of the promising properties of rocks for estimating mechanical properties of rocks in a nondestructive manner.
• 乾燥による岩石の物理的性質の変化に関する室内試験

  白木文香, 川﨑 了, 金子勝比古

  第33回岩盤力学に関するシンポジウム講演論文集 283 - 288 2004 [Not refereed][Not invited]
  
• Estimation method for weathering thickness of man-made weathering rocks by using the Equotip hardness tester

  Kawasaki, S, Kaneko, K

  Proceedings of the ISRM Regional Symposium EUROCK 2004 and 53rd Geomechanics Colloquy 491 - 494 2004 [Not refereed][Not invited]
  
• Influence of the rock mass inhomogeneity caused by layer geometry on the regional stress field

  Cho, S.H, Nakamura, K, Kawasaki, S, Yang, H.S, Sato, M, Nakama, S, Kaneko, K

  Tunnel and Underground Space, Journal of Korean Society for Rock Mechanics 14 (2) 142 - 153 2004 [Refereed][Not invited]
  
• Effect of Water Content on Color and Physical Properties of Rocks

  Kawasaki Satoru, Shiraki Fumika, Kaneko Katsuhiko

  Proceedings of the Japan National Conference on Geotechnical Engineering 公益社団法人 地盤工学会 39 561 - 562 2004 

  Generally, physical properties of rocks are affected by changes of water content, and it is well known that the effect of water content of soft rocks, which have relatively large void ratios, is still larger than that of hard rocks. In order to investigate the effect of water content on physical properties of rocks, color and several physical properties of rocks were measured under the water-saturated and dry conditions. As a conclusion, it is expected that there is a possibility that P-wave velocity and rebound hardness of rocks may be able to estimate by using brightness difference of rocks.
• 分光測色計を用いた鉱物および岩石の色測定

  千引春菜, 川﨑 了, 金子勝比古

  第32回岩盤力学に関するシンポジウム講演論文集 323 - 328 2003 [Not refereed][Not invited]
  
• Estimation of regional stress and stress distribution

  S Kawasaki, K Nakamura, T Sato, S Nakama, K Kaneko

  ROCK STRESS 419 - 424 2003 [Not refereed][Not invited]
   

  A method for estimating the global stress field from the local stress field evaluated by the field initial stress measurement is discussed. As for numerical analysis of rock stress measurement, few research examples quantitatively evaluate inhomogeneity of the three dimensional initial stress fields in rock masses. In order to grasp the effect of inhomogeneity of rock masses, a homogeneous rock model and an inhomogeneous rock model including different strata were made and the global stress fields were estimated. Furthermore, the method of back analysis of global strains was investigated by using plural stress measuring points in the region specified. As a result of these analyses, it was found that analyses of stress states in deep rock masses required consideration of structures and mechanical properties of each stratum.
• 人工風化岩を用いた簡易反発硬度試験

  阿部右吾, 川﨑 了, 金子勝比古

  第32回岩盤力学に関するシンポジウム講演論文集 329 - 334 2003 [Not refereed][Not invited]
  
• Evaluation of rock mass elastic constants by using earthmover load

  S Kawasaki, K Kaneko, Y Obara, N Nakamura, R Tsukayama

  FIELD MEASUREMENTS IN GEOMECHANICS 513 - 518 2003 [Not refereed][Not invited]
   

  Using an earthmover as a loading source, an estimation method of elastic constants of rock masses is discussed. For regional rock masses, it is obvious that suitable large loads are required for field measurements of rock mass deformation. The present in-situ loading tests have, however, the limits of improving and scaling up of machinery and tools because of mechanical structure and/or economy of loading apparatus. It is, therefore, necessary to develop another different methodology from usual. Provided that an earthmover; which is generally used in a quarry, can be used as the weight of loading, loading tests of rock masses can be carried out without special and additional loading equipment. In anticipation of very small,deformation of the regional rock masses, deformation measurements with high accuracy are demanded. Consequently, the authors tried to solve this problem, by using a high-resolution tilt meter.
• Shear characteristics of rock joints under constant dilatancy

  Tanimoto, C, Suzuki, J, Kawasaki, S, Nakahara, T

  Journal of Geotechnical Engineering, Japan Society of Civil Engineers 公益社団法人 土木学会 2003 (736) 93 - 102 0289-7806 2003 [Refereed][Not invited]
   

  In consideration of allowable limit of displacement and deformation associated with rock tunnelling, we should pay more attention to the meaning of the shear behavior of rock joints under constant dilatancy. By employing about 250 specimens which were made of three materials and reproduced from several natural joints with different roughnesses, the authors have carried out direct shear tests under constant dilatancies. The breakage of joint asperity was discussed from the point of view standing on the relationship between shear strength and the loss of asperity. The method to estimate the volume of fractured asperities was proposed and the correlation between shear strength and the volume was discussed. Finally, the authors proposed the new relational expression between the volume of fractured asperities and the shear strength.
• Shear Strength of Rock Joint under Constant Pressured and Constant Dilatancy.

  TANIMOTO Chikaosa, KITAMURA Yoshinori, KAWASAKI Satoru, MIYATA Kenjiro, SUZUKI Junya

  Doboku Gakkai Ronbunshu 公益社団法人 土木学会 2002 (715) 83 - 94 0289-7806 2002 [Refereed][Not invited]
   

  The shear strength of a rock joint has been focussed by many engineers over several decades. So far as the authors know, there are many publications concerning the shear test under constant normal load and/or stiffness. In consideration of allowable limit of displacement/deformation associated with rock tunnelling, we should pay more attention to the meaning of the shear behavior of rock joints under constant dilatancy than the one under constant normal load and stiffness, which is much far from the reality in rock tunneling with loosening phenomenon. By employing more than 140 specimens which were reproduced from 20 natural joints with different roughnesses, the authors have carried out direct shear tests under both constant pressures and dilatancies.
  The breakage of joint asperity was discussed from the point of view standing on the relationship between the loss of asperity and mobilized shear strength. The change of shear strength from the peak to the residual strength has been clarified and the appropriate installation of supporting elements in rock tunnelling was discussed.
• Shear strength and propagation of seismic wave during rock joint shear test under constant pressure and constant dilatancy

  Tanimoto, C, Miyata, K, Kawasaki, S, Kitamura, Y, Suzuki, J

  Journal of Geotechnical Engineering, Japan Society of Civil Engineers 公益社団法人 土木学会 2002 (715) 95 - 105 0289-7806 2002 [Refereed][Not invited]
   

  Through the long term running research conducted by the prime author, it has been clarified that, when seismic wave propagated through rock joints, the change of amplitude showed more sensitive than that of propagating velocity. Basing on this observation, the authors carried out the measurement of the velocity and amplitude of propagating wave during the rock joint shear test. It was confirmed that the monitoring by means of the change of amplitude of propagating wave could show the progress of loosening during excavation. The final objective of the research is to estimate the magnitude of loosening phenomenon in quantitative manner which is essential in rock tunneling.
• An attempt to estimate mechanical properties of rocks using the Equotip hardness tester

  Kawasaki, S, Tanimoto, C, Koizumi, K, Ishikawa, M

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 43 (4) 244 - 248 0286-7737 2002 [Refereed][Not invited]
   

  The Equotip hardness tests, unconfined compression tests and elastic wave tests were conducted using rock cores sampled from several sites in Japan, and a consideration of correlations between obtained hardness indexes and mechanical properties was carried out. As a result, it was found that there was a fair possibility of estimating the values of unconfined compressive strength using hardness indexes.
• The development of property evaluation method for rock materials based on the simple rebound hardness test: Investigations on the effects of test conditions and fundamental properties

  S Kawasaki, M Yoshida, C Tanimoto, T Masuya

  ROCK MECHANICS: A CHALLENGE FOR SOCIETY 103 - 108 2001 [Not refereed][Not invited]
   

  The Equotip hardness tester is one of the useful testers developed so as to understand elastic properties and strengths of metallic materials. It is picked up as the characteristics of the rester that a small sample is needed for the test, sampling time is short, and the tester is convenient for portable use. In case of applying the rester to an actual structure constructed in or on rock mass and a stone cultural heritage whose shape is complex, it is therefore expected that the tester is able to measure rapidly toward all test directions in the field. For the purpose of newly developing an evaluation method for rock materials using the tester, this paper reports on especially two objects such as 1) investigations on the effects of test conditions (i.e. considerations on the size, shape and roughness of rock samples), and 2) investigations on fundamental properties of unweathered rock samples (i.e. considerations on the relationships to physical and mechanical properties).
• 風化岩を対象とした簡易反発硬度試験の適用性

  吉田昌登, 川﨑 了, 谷本親伯, 舛屋 直

  第31回岩盤力学に関するシンポジウム講演論文集 97 - 101 2001 [Not refereed][Not invited]
  
• Deterioration phenomena and conservation methods of stone Buddha images in Japan

  S Kawasaki, C Tanimoto

  FRONTIERS OF ROCK MECHANICS AND SUSTAINABLE DEVELOPMENT IN THE 21ST CENTURY 413 - 416 2001 [Not refereed][Not invited]
   

  The authors have investigated the deterioration phenomena, conservation and restoration of stone cultural heritages from the viewpoint of rock mechanics. This paper shows the state of the art of deterioration examinations, conservation and restoration of stone Buddha images in Japan.
• エコーチップ反発硬度試験の岩石材料への適用性

  吉田昌登, 川﨑 了, 谷本親伯, 舛屋 直

  第30回岩盤力学に関するシンポジウム講演論文集 308 - 312 2000 [Not refereed][Not invited]
  
• The development of property evaluation method for rock materials based on the simple rebound hardness test: Investigations on the effects of test conditions and fundamental properties

  Kawasaki, S, Yoshida, M, Tanimoto, C, Masuya, T

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 41 (4) 230 - 241 0286-7737 2000 [Refereed][Not invited]
   

  The Equotip hardness tester made in Switzerland is one of the testers developed so as to understand elastic properties and strengths of metallic materials. It is picked up as the characteristics of the tester that a small sample is needed for the test, sampling time is short, and the tester is convenient for portable use. In case of applying the tester to an actual rock structure and a lithic cultural heritage whose shape is complex, it is therfore expected that the tester is able to measure rapidly toward all test directions in the fied. For the purpose of newly developing an evaluation method for rock materials using the tester, this paper reports on especially two objects such ad (1)investigations on the effects of test conditions(considerations on the size, shape and roughness of rock samples), and (2)investigations on fundamental properties of unweathered rock samples(considerations on the relationships to physical and mechanical properties).
• 不連続性岩盤の弾性波伝播特性に関する検討

  宮田健治朗, 谷本親伯, 川﨑 了, 舛屋 直

  第30回岩盤力学に関するシンポジウム講演論文集 178 - 182 2000 [Not refereed][Not invited]
  
• 室内試験による岩石の比抵抗に関する基礎的研究

  西澤亮総, 谷本親伯, 川﨑 了, 舛屋 直

  第30回岩盤力学に関するシンポジウム講演論文集 188 - 192 2000 [Not refereed][Not invited]
  
• 岩盤不連続面の表面形状の定量化とせん断強度の推定に関する研究

  北村義宜, 谷本親伯, 川﨑 了, 舛屋 直

  第30回岩盤力学に関するシンポジウム講演論文集 348 - 352 2000 [Not refereed][Not invited]
  
• 二種混合体の圧縮特性に関する解析的検討－礫岩の強度評価へのアプローチ－

  中本 崇, 西村 強, 川﨑 了, 木山英郎

  第30回岩盤力学に関するシンポジウム講演論文集 338 - 342 2000 [Not refereed][Not invited]
  
• Quality evaluation of deep conglomerate core samples based on laboratory tests

  Kawasaki, S, Nakagawa, K, Eto, Y, Nozaki, A, Koizumi, K

  Journal of Geotechnical Engineering, Japan Society of Civil Engineers 公益社団法人 土木学会 617 (617) 77 - 87 0289-7806 1999 [Refereed][Not invited]
   

  In case of constructing underground structures in deep conglomerate, it is considered that strength and deformation properties of conglomerate core samples are occasionally overestimated because of gravel effect, while the properties are underestimated because of sample disturbance by core sampling. A series of laboratory tests was therefore performed using deep conglomerate core samples and the quality evaluation of the samples was conducted. In this paper, it is presented that the sample disturbance which gives influences to the quality of the samples is complicatedly concerned with gravel fraction content and calcite content. Especially the smaller the calcite content and the gravel fraction content are, the more extensively the sample disturbance is influenced.
• Quality evaluation of conglomerate core samples based on laboratory tests

  S Kawasaki, H Ito, K Nakagawa, Y Eto, A Nozaki, K Koizumi

  NINTH INTERNATIONAL CONGRESS ON ROCK MECHANICS, VOLS 1 & 2 619 - 622 1999 [Not refereed][Not invited]
   

  To conduct a quality evaluation of conglomerate core samples, a series of laboratory rock tests using conglomerate core samples obtained from the depth of 600m and artificial conglomerate core samples was carried out. This paper shows that the sample disturbance by core sampling which gives influences to the quality of conglomerate core samples is complicatedly concerned with gravel faction content and calcite content. Especially the smaller the calcite content is, and moreover, the smaller the gravel fraction content is, the more extensively the sample disturbance by core sampling is influenced.
• Measurement method of gravel fraction content of conglomerate by image data processing

  Kawasaki, S, Koizumi, K

  Journal of Japan Society of Engineering Geology 39 (2) 202 - 207 0286-7737 1998 [Refereed][Not invited]
  
• Evaluation on scale effect of conglomerate core sample and disturbance by core sampling

  Kawasaki, S, Ito, Y, Koizumi, K

  Journal of Japan Society of Engineering Geology, 39 (4) 391 - 400 0286-7737 1998 [Refereed][Not invited]
  
• 大深度堆積礫岩の力学特性－室内試験による礫岩コアの品質評価－

  川﨑 了, 中川加明一郎, 江藤芳武, 野崎明人, 小泉和広

  第10回岩の力学国内シンポジウム講演論文集 797 - 802 1998 [Not refereed][Not invited]
  
• An attempt to estimate coefficient of permeability by taking notice of consolidation phenomenon on sedimentary rock

  Kawasaki, S, Nakagawa, K, Koizumi, K

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 39 (3) 273 - 281 0286-7737 1998 [Refereed][Not invited]
   

  From the viewpoint that the principle of effective stress can apply to rocks, an attempt to estimate coefficients of permeability of rocks was performed by measuring of consolidation phenomenon like soil materials. Specimens were sedimentary rocks, i.e., soft mudstone and hard conglomerate. This attempt led to the conclusion that close agreement between coefficients of permeability measured by isotropic consolidation tests and injection tests was seen. It is a special merit of this estimation method for coefficient of permeability that a triaxial test with a consolidation test is enough to obtain coefficient of permeability without a laboratory permeability test. This simple estimation method is therefore considered one of effective methods.
• Investigation on mechanical properties of sedimentary ground at great depth in consideration of consolidation history

  Kawasaki, S, Nishi, K, Okamoto, T

  Journal of Geotechnical Engineering, Japan Society of Civil Engineers 土木学会 589 (589) 79 - 90 0289-7806 1998 [Refereed][Not invited]
  
• 軟岩地盤での圧縮空気貯槽建設コストのパラメトリックスタディ

  川﨑 了, 岡本敏郎, 田中幸久

  地下空間シンポジウム論文・報告集 2 175 - 179 1997 [Not refereed][Not invited]
  
• Feasibility of compressed air energy storage in deep soft rock ground - Application of the slurry excavation and steel pipe shaft method

  S Kawasaki, T Okamoto, Y Tanaka, S Hibino

  TUNNELS FOR PEOPLE, VOLS 1 AND 2 835 - 840 1997 [Not refereed][Not invited]
   

  The CAES-GT system, in which a compressed air energy storage cavern constructed in deep ground is combined with a gas turbine generator, is attracting wide attention. The feasibility of this CAES-GT system depends on whether it is economic to construct a compressed air energy storage facility deep underground. This paper shows the characteristics and feasibility of construction method for compressed air storage facilities in deep soft rock ground.
• Measurement of pore pressure distribution in deep rock and its application to estimating underground water flow

  Nakagawa, K, Kawasaki, S, Shidahara, T, Eto, Y, Nozaki, A

  Proceedings of the International Symposium on Rock Mechanics and Environmental Geotechnology 477 - 481 1997 [Not refereed][Not invited]
  
• An attempt of property classification of deep sedimentary conglomerate by using core samples

  Kawasaki, S, Nakagawa, K, Eto, Y, Nozaki, A, Koizumi, K

  Journal of Japan Society of Engineering Geology 38 (5) 296 - 298 0286-7737 1997 [Refereed][Not invited]
  
• Consideration of deep sedimentary conglomerate properties by taking notice of the calcite content

  Kawasaki, S, Nakagawa, K, Eto, Y, Nozaki, A, Koizumi, K

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 38 (5) 252 - 264 0286-7737 1997 [Refereed][Not invited]
   

  To investigate deep conglomerate properties, a deep boring of the depth of 600 m and a series of laboratory rock tests were performed. And we especially took notice of the calcite content considered a large influence on mechanical properties of conglomerate. A quantity measuring of the calcite content was tried to research relationships between the calcite content and mechanical properties of conglomerate. These results led to the conclusion that it was clear that laboratory test results of deep sedimentary conglomerate were able to be evaluated by considering t, he calcite content and the influence of looseness by stress release on conglomerate core samples.
• 大深度軟岩地盤における立坑掘削挙動を模擬した室内模型実験

  川﨑 了, 岡本敏郎, 田中幸久

  第27回岩盤力学に関するシンポジウム講演論文集 111 - 115 1996 [Not refereed][Not invited]
  
• Feasibility and characteristics of Compressed Air Energy Storage-Gas Turbine generation in soft rock ground: Application of muddy slurry excavation and steel pipe shaft construction method in great depth

  Okamoto, T, Tanaka, Y, Kawasaki, S, Hibino, S

  Journal of Japan Society of Engineering Geology 一般社団法人日本応用地質学会 35 (6) 264 - 272 0286-7737 1995 [Refereed][Not invited]
   

  Geological conditions should be considered when a storage cavern is constructed in rock ground for compressed air energy storage gas turbine generator which is hopeful as electric power storage in near future, and muddy slurry excavation and steel pipe shaft method is proposed in soft rocks. The water replacement type and dry type are typical in the method and their basic characteristics are studied in this paper. Most important things in realizing this method are both feasibility of excavating a cavern and its economic advantage, especially present evaluation of cavern stability in muddy slurry excavation and economically optimum depth in positioning a cavern are studied in this paper.
• 定ひずみ速度圧密試験法の堆積軟岩への適用

  川﨑 了, 西 好一, 高橋 浩

  第25回岩盤力学に関するシンポジウム講演論文集 126 - 130 1993 [Not refereed][Not invited]
  
• MECHANICAL-PROPERTIES OF DEEP SOFT ROCK GROUND IN THE SUBURBS OF TOKYO

  S KAWASAKI, K NISHI, Y FUJIWARA

  GEOTECHNICAL ENGINEERING OF HARD SOILS - SOFT ROCKS, VOL 1 593 - 600 1993 [Not refereed][Not invited]
  
• Construction technology of compressed air storage tank in soft rock ground for CAES-GT generation

  Nishi, K, Kawasaki, S, Fujiwara, Y, Hibino, S

  Proceedings of the 2nd International Compressed Air Energy Storage Conference 1 - 16 1992 [Not refereed][Not invited]
  

Books etc

• Organic-Inorganic Hybrid Green Materials for Soil Improvement. In: Chinnappan Baskar, Seeram Ramakrishna, Angela Daniela La Rosa (eds.) Encyclopedia of Green Materials

  Thiloththama Hiranya Kumari Nawarathna, Sivakumar Gowthaman, Kazunori Nakashima, Satoru Kawasaki 
  Springer Nature Singapore 2022/01 (ISBN: 9789811649219)
• Stabilization/solidification of mining waste via biocementation. In: Daniel C.W. Tsang, Lei Wang (eds) Low Carbon Stabilization and Solidification of Hazardous Wastes

  Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki 
  Elsevier, Netherlands 2021/09
• Biocementation technology for stabilization/solidification of organic peat. In: Daniel C.W. Tsang, Lei Wang (eds.) Low Carbon Stabilization and Solidification of Hazardous Wastes

  Sivakumar Gowthaman, Meiqi Chen, Kazunori Nakashima, Shin Komatsu, Satoru Kawasaki 
  Elsevier, Netherlands 2021/09
• The Amendments in Typical Microbial Induced Soil Stabilization by Low-Grade Chemicals, Biopolymers and Other Additives: A Review. In: V. Achal and C. S. Chin (eds.) Building Materials for Sustainable and Ecological Environment

  Sivakumar Gowthaman, Thiloththama Hiranya Kumari Nawarathna, Pahala Ge Nishadi Nayanthara, Kazunori Nakashima, Satoru Kawasaki 
  Springer, Singapore 2021/05
• 地盤材料試験の方法と解説（第一回改訂版）

  地盤工学会 2020/12
• Effect of Plant-Derived Urease-Induced Carbonate Formation on the Strength Enhancement of Sandy Soil. In: Achal V., Mukherjee A. (eds) Ecological Wisdom Inspired Restoration Engineering

  Dilrukshi R.A.N, Kawasaki S 
  Springer, Singapore 2018/08
• Utilization of Microbially Induced Calcite Precipitation for Sand Solidification Using Pararhodobacter sp.. In: Achal V., Mukherjee A. (eds) Ecological Wisdom Inspired Restoration Engineering

  Amarakoon G.G.N.N, Kawasaki S 
  Springer, Singapore 2018/08
• Making Artificial Beachrock Through Bio-cementation: A Novel Technology to Inhibition of Coastal Erosion. In: Hussain C. (eds) Handbook of Environmental Materials Management

  Khan M.N.H, Kawasaki S 
  Springer, Cham 2018/01
• 地盤材料試験の方法と解説

  地盤工学会 2009
• 岩の試験・調査方法の基準・解説書－平成18年度版－

  地盤工学会 2006
• 『残壁ハンドブック』<資源・素材学会残壁ハンドブック編集委員会>

  資源・素材学会 2005
• 岩の試験・調査方法の基準・解説書－平成14年度版－

  地盤工学会 2003
• 『ロックメカニクス』<日本材料学会編>

  技報堂出版 2002

MISC

• マイクロフォーカスX線CTを用いた地下圏バイオメタン生成に関する褐炭の微細構造変化の観察

  田中翔, 福田大祐, 川崎了, 荒牧憲隆, 金子勝比古  資源・素材(Web)  2015-  2015
• 函館市豊崎町における落石メカニズム解明を目的とした長期モニタリング対象の旧道岩盤斜面を構成する岩石の特徴

  冨樫晃平, 小玉齊明, 山真典, 菅原隆之, 畠山葵, 福田大祐, 加藤昌治, 川崎了, 藤井義明  資源・素材学会春季大会(Web)  2014-  2014
• Aging behaviour of organic matter decomposition and microstructure of coal in hydrogen peroxide solution

  荒牧 憲隆, 玉村 修司, 田中 翔, 清水 了, 上野 晃生, 川崎 了, 金子 勝比古  地盤工学シンポジウム論文集 地盤工学会 編  59-  539  -546  2014
• New Soil Improvement Technology Merged with Biological and Chemical Engineering : New Challenges for the High Organic Soil Like Peat

  畠 俊郎, 佐藤 厚子, 川崎 了, 阿部 廣史  地盤工学会誌  62-  (1)  32  -33  2014
• 11. Sand solidification test using ureolytic bacteria, Pararhodobacter sp.

  Danjo Takashi, Kawasaki Satoru, Shimazaki Suguru, Koizuka Keisuku  研究発表会講演論文集  26-  21  -22  2014
• 地盤工学会論文賞(和文部門)を受賞して

  稲垣 由紀子, 塚本 将康, 森 啓年, 中島 進, 佐々木 哲也, 川崎 了  地盤工学会誌 = / the Japanese Geotechnical Society  60-  (8)  38  -38  2012/08/01
• X-ray Computed Tomography Image Segmentation of Three Phase Composites Considering Partial Volume Effect

  KATO Masaji, YAMANAKA Hiroshi, TAKAHASHI Manabu, KAWASAKI Satoru, KANEKO Katsuhiko  情報地質 = Geological data processing  23-  (2)  78  -79  2012/06/15  [Not refereed][Not invited]
  
• P25. Understanding Formation Mechanisms of Beachrocks

  Danjo Takashi, Kawasaki Satoru, Hata Toshiro  研究発表会講演論文集  24-  189  -190  2012
• マイクロフォーカスX線CTによる二相構造画像の二値化に関する基礎的検討

  山中裕史, 川崎了, 加藤昌治, 金子勝比古  資源・素材学会北海道支部春季講演会講演要旨集  2010-  15  -16  2010  [Not refereed][Not invited]
  
• Extraction of Porosity Change of Geomaterials Using X-ray CT Images

  KATO Masaji, KOBAYASHI Yuya, KAWASAKI Satoru, KANEKO Katsuhiko  情報地質 = Geological data processing  20-  (2)  112  -113  2009/06/18  [Not refereed][Not invited]
  
• X線CT法を用いたバイオグラウト処理された供試体内部の定量化の試み

  小林優矢, 川崎了, 加藤昌治, 金子勝比古, 椋木俊文  資源・素材学会北海道支部春季講演会講演要旨集  2009-  13  -14  2009  [Not refereed][Not invited]
  
• X線CT法を用いたバイオグラウト処理された供試体内部の評価

  小林優矢, 川崎了, 加藤昌治, 金子勝比古, 椋木俊文  資源・素材  2009-  12  2009  [Not refereed][Not invited]
  
• メタ珪酸ナトリウムを用いたバイオグラウト

  小林 元, 川崎 了, 広吉 直樹, 恒川 昌美, 金子 勝比古, 島田 俊介  春季大会講演集. I, 資源編  19-  (2)  73  -74  2007/03/29
• 静水圧条件と三軸圧縮条件における堆積岩の変形挙動と間隙水の排水挙動との関係

  上野 悠也, 加藤 昌治, 高橋 学, 川崎 了, 金子 勝比古  春季大会講演集. I, 資源編  19-  (1)  37  -38  2007/03/29  [Not refereed][Not invited]
  
• P42. Fundamental study on biogrout using sodium metasilicate

  KOBAYASHI Gen, KAWASAKI Satoru, HIROYOSHI Naoki, TSUNEKAWA Masami, KANEKO Katsuhiko, TERAJIMA Rei, SHIMADA Shunsuke  研究発表会講演論文集  19-  229  -230  2007
• 研究室紹介 北海道大学大学院工学研究科 環境フィールド工学専攻 大気地圏環境工学講座 地圏フィールド工学研究室

  金子 勝比古, 川崎 了  石灰石  (338)  21  -29  2005/11
• 63. Soil Improvement Tests on Sealability Using Biogrout

  Kawasaki Satoru, Murao Akira, Hiroyoshi Naoki, Tsunekawa Masami, Kaneko Katsuhiko  研究発表会講演論文集  17-  221  -222  2005
• P17. Estimation of Physical Properties of Rocks Using Brightness Difference

  Kawasaki Satoru, Shiraki Fumika, Kaneko Katsuhiko  研究発表会講演論文集  17-  329  -330  2005
• 乾燥による岩石の物理的性質の変化

  川崎 了, 白木 文香, 金子 勝比古  春季大会講演集. I, 資源編  16-  (1)  "企画  -174"-"企画-175"  2004/03/29
• 地盤内三次元応力分布の評価法

  栗栖 圭太郎, 中村 圭太, 川崎 了, 金子 勝比古, 佐藤 稔紀, 中間 茂雄  春季大会講演集. I, 資源編  16-  (1)  13  -14  2004/03/29  [Not refereed][Not invited]
  
• 三次元広域応力場の解析手法に関する研究

  中村 圭太, 川崎 了, 金子 勝比古, 佐藤 稔紀, 中間 茂雄  春季大会講演集. I, 資源編  15-  (1)  189  -190  2003/03/27  [Not refereed][Not invited]
  
• エコーチップ硬さ試験機による岩石の一軸圧縮強度の推定

  川崎了  土木学会年次学術講演会講演概要集第3部, 2002  57-  887  -888  2002
• 40275 Extraction of bamboo species in southern areas of Kyoto prefecture using satellite data.

  KOIZUMI Keigo, TANIMOTO Tikaosa, KAWASAKI Satoru, PIAO Chunze, AZUMADA Kensuke, OHASHI Naohiro  Summaries of technical papers of Annual Meeting Architectural Institute of Japan. D-1, Environmental engineering I, Room acoustics and acoustic environment noise and solidborne sound environmental vibration light and color water supply and drainage water environment urban installation and environmental management environmental psychology and physiology environmental design electro-magnetic environment  2001-  567  -568  2001/07/31
• 「圧密履歴を考慮した大深度堆積地盤の力学的特性に関する考察」への討議・回答

  龍岡 文夫, 川崎 了, 西 好一, 岡本 敏郎  土木学会論文集 = Proceedings of JSCE  624-  293  -297  1999/06/21
• Granular Assembly Simulation for Compression Strength of Mixed Circular Elements Using DEM

  Nakamoto Takashi, Kawasaki Satoru, Kiyama Hideo, Fujimura Hisashi, Nishimura Tsuyoshi  Reports of the Faculty of Engineering, Tottori University  29-  (1)  119  -124  1998/11
• 定ひずみ速度圧密試験法の堆積軟岩への適用

  川崎了  第27回土質工学研究発表会  1231  -1232  1992
• Distinct Element Analysis of Fractured Rock Mass with the Auto Element Tessellation

  木山 英郎, 藤村 尚, 西村 強, 川崎 了  Reports of the Faculty of Engineering,Tottori University  18-  (1)  p121  -127  1987/11

Industrial Property Rights

• 特願2016-157306:海岸・河岸保全工法  2016年/08/10

  川﨑 了, 宇次原雅之
• 特許公開2012-172060:グラウトおよび地盤を固結する方法  2012/09/10

  川﨑 了, 秋山 克
• 特許4621634:微生物を用いたカルシウムを含む地盤の固結方法    2011/01/26

  川﨑 了, 廣吉直樹, 島田俊介, 小山忠雄, 寺島 麗  

  特開2008-8023
• 特許4608669:微生物を用いたカルシウムを含む地盤改良方法    2011/01/12

  川﨑 了, 廣吉直樹, 島田俊介, 小山忠雄, 寺島 麗  

  特許公開2008-184741
• 特許4599611:地盤改良工法およびその工法に用いるグラウト    2010/12/15

  川﨑 了, 廣吉直樹  

  特許公開2006-169940
• 特許4517050:地盤改良方法及びその装置    2010/05/28

  川﨑 了, 廣吉直樹, 島田俊介, 小山忠雄, 寺島 麗  

  特許公開2008-231769
• 特願2007-27076:気泡ボーリング用気泡剤  2007年/02/06

  川﨑 了, 小宮国盛  

  特許公開2008-190251
• 特許公開2001-200526:微生物による構造物材料の風化加速方法  2001/07/27

  川﨑 了, 武田克史  

  特開2001-200526
• 特許公開2001-200525:微生物による構造物材料の物性改良方法  2001/07/27

  川﨑 了, 武田克史  

  特開2001-200525
• 特許公開平11-236708:ワイヤーラインによるセルフボーリング型プレッシャーメータ試験方法  1999/08/31

  川﨑 了  

  特開平11-236708
• 特開2008-63495:土または建造物躯体の処理方法  

  島田俊介, 小山忠雄, 寺島 麗, 川﨑 了, 廣吉直樹  

  特許公開2008-63495

Awards & Honors

• 2021/11 The GEOMATE International Society The Eleventh International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2021) Best Paper Award
  
• 2018/11 The GEOMATE International Society The Eighth International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2018) Best Paper Award
  
• 2016/02 Hokkaido University Hokkaido University President's Award for Outstanding Education
   

  受賞者: KAWASAKI Satoru
• 2012/11 The GEOMATE International Society The Second International Conference on Geotechnique, Construction Materials and Environment (GEOMATE 2012) Keynote Paper Award
   

  受賞者: KAWASAKI Satoru
• 2012/06 Japanese Geotechnical Society FY2011 Paper Awards (Japanese section) of Japanese Geotechnical Society
  
• 2008/05 Japan Society of Engineering Geology The 18th Paper Awards of Japan Society of Engineering geology
   

  受賞者: Kawasaki, S

Research Grants & Projects

• Eco-friendly biocementation of geomaterials using acid urease and bone meal

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2022/04 -2025/03 

  Author : Satoru Kawasaki
• 天然および人工の有機・無機接着界面から発想する新たなバイオベース固化技術の創出

  日本学術振興会：科学研究費助成事業

  Date (from‐to) : 2021/04 -2024/03 

  Author : 中島 一紀, 川崎 了, 五十嵐 健輔
• Development of biocementation technology for self-healing with selective and concentrative function

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2021/04 -2024/03 

  Author : 松原 仁, 川崎 了, 椋木 俊文

   

  脆弱化した岩石の自己組織的な新しい修復技術の構築に向けて，フィールド調査，室内実験，X線画像解析，シミュレーションの観点からの研究を進めており，2021年度の活動は以下のようにまとめることができる。 (1)上期に沖縄本島・離島および北海道にて事前の露頭調査を実施し，詳細調査の対象とする砂岩および凝灰岩露頭を選定した。そして，夏期および冬期には，沖縄本島・離島で選定した露頭の詳細調査を実施し，環境因子（気温，湿度，光量子密度），マクロ強度，鉱物組成（XRD），分子質量数（MS，ICP発光分析），微細構造（SEM），岩内微生物の菌叢構造（NGS）を得た。 (2)セルロース繊維材としてバイオ炭（炭化木材，炭化バガス）を選定し，地盤固化を可能とするSporosarcina pasteuriiの活性化実験を実施した。結果として，改良の余地は多く残されているものの，活性化できる可能性を見出した。また，微弱電流の添加については，通電のみでも脆弱化した岩石を修復できる可能性を見出した。微生物なしの予備実験を実施したところ，多孔質岩の空隙部に炭酸塩が析出し，岩石の強度を高めることが明らかとなった。 (3)硅砂5号をSporosarcina pasteuriiおよび沖縄県内から採取した尿素分解菌を使って固化させた供試体を製作しした。そして，ナノX線CTスキャナーで撮影することにより，砂粒子と炭酸カルシウムの3次元構造を個別に得ることに成功した。 (4)MICP（microbially induced carbonate precipitation）のプロセスにおいて，微生物代謝および挙動，炭酸塩の析出，土粒子・間隙水の電場を考慮したマルチフィジックス・マルチスケール解析法を構築した。シミュレーションにて得られた炭酸塩の析出パターンは実験値に酷似し，析出量も実験と同等の値となることを確認した。
• Development of new slope protection technologies using biocementation by focusing on locality

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2019/04 -2022/03 

  Author : Satoru Kawasaki

   

  This study aimed to develop a new slope protection method of CaCO3 precipitation to solidify the surface soil of a slope, and to confirm the effectiveness of this method by focusing on the regional characteristics of microorganisms inhabiting the soil around the application site of the slope protection works. A bacterial strain suitable for CaCO3 precipitation was identified in the surface soil of a slope in Hokkaido, Japan through screening for ureolytic bacteria suitable for biocementation in cold regions. The CaCO3 precipitation characteristics of this bacterial strain were investigated, and laboratory solidification tests using syringes and slope models were conducted using geomaterials with different particle size distributions. Furthermore, a field trial was conducted on the surface soil of a slope in Hokkaido, Japan. In conclusion, the effectiveness of the newly developed method was confirmed.
• Consolidated bioremediation of heavy metal contamination using biocementation and biomass

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2018/04 -2021/03 

  Author : Kazunori Nakashima

   

  The objective of this study is to develop a system that can immobilize soil contaminated with high concentration of heavy metals using bio-cement technique, and completely remove a trace amount of heavy-metal ions in water using heavy-metal-binding biomass. Precipitation of CaCO3 using urease-producing bacteria was successfully applied for solidification and immobilization of heavy metals in a model and actual contaminated soil samples. Furthermore, bio-cement combined with organic polymers was developed to increase the strength of biocemented sample. Novel heavy metal adsorbents based on protein and natural polymers were developed, and a continuous adsorption system was constructed.
• Development of a new land restoration and conservation technology learned from beachrock formation mechanism

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

  Date (from‐to) : 2016/04 -2019/03 

  Author : KAWASAKI SATORU

   

  The purpose of this study was to develop man-made beachrocks cemented by precipitated CaCO3, which were produced by using natural coastal materials. This technique endowed the man-made beachrocks with an unconfined compressive strength (UCS) of approximately 20-30 MPa after approximately one month of curing. The technique was newly developed in this study and validated for its effectiveness. A search for ureolytic bacteria that yield high urease activity was conducted in coastal areas in Japan. Several types of discovered bacteria that exhibited suitable properties for precipitating CaCO3 were isolated from soil samples in areas such as Okinawa prefecture and Hokkaido. Accelerated laboratory solidification tests on sand samples were performed using the bacteria. The results demonstrated that after three weeks, the samples yielded approximately 20 MPa of UCS as measured in needle penetration tests. In conclusion, the effectiveness of the newly developed technique was validated.
• 自然に学ぶ新しい国土修復保全技術に関する基礎的研究

  鹿島学術振興財団：2016年度 研究助成（継続）

  Date (from‐to) : 2017/04 -2018/03 

  Author : 川﨑 了
• 現地の微生物を利用した新しい地盤固化技術の実証

  イムラ・ジャパン株式会社：先進技術シーズ研究への研究助成「第1回イムラ・ジャパン賞」助成金

  Date (from‐to) : 2017/04 -2018/03 

  Author : 川﨑 了
• Evaluation and designing of adsorption layer method for countermeasures against excavated rocks

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2014/04 -2017/03 

  Author : Igarashi Toshifumi, TAMOTO Shuichi

   

  Column experiments consisting of covering soil, crushed rock containing arsenic, and bottom adsorption layers were conducted in the laboratory to understand the leaching and migration of arsenic in relation to changes in water content and oxygen concentration. The results showed that the arsenic leaching was affected by water content and oxygen concentration. In addition, arsenic retardation was found to consist of both conventional reversible and irreversible adsorptions. The irreversible one results from the precipitation of iron hydroxides in the columns. The similar results were obtained in the in situ column experiments. The Hydrous1-D model was revised by considering the relationships. The leaching and migration of arsenic was evaluated by the revised model using the obtained parameters. This model will be effective in designing the adsorption layer method.
• 自然に学ぶ新しい国土修復保全技術に関する基礎的研究

  鹿島学術振興財団：2015(平成27)年度 研究助成

  Date (from‐to) : 2016/04 -2017/03 

  Author : 川﨑 了
• 現地の微生物を利用した国土の新しい自己修復保全技術の開発

  八洲環境技術振興財団：平成27年度 研究開発・調査助成

  Date (from‐to) : 2016/04 -2017/03 

  Author : 川﨑 了
• 自然のビーチロック形成メカニズムに学ぶ国土の自己修復保全に関する技術開発

  住友財団：2015年度 環境研究助成

  Date (from‐to) : 2015/11 -2016/10 

  Author : 川﨑 了
• ビーチロックに学ぶ国土修復保全技術の開発

  積水化学工業：積水化学 自然に学ぶものづくり研究助成プログラム

  Date (from‐to) : 2015/10 -2016/09 

  Author : 川﨑 了
• ビーチロックに学ぶ新しい国土修復保全技術の開発

  戸田育英財団：平成27年度研究助成

  Date (from‐to) : 2015/07 -2016/03 

  Author : 川﨑 了
• 自然に学ぶ海岸構造物の自己修復技術に関する研究

  国土技術研究センター：平成26年度（第16回）国土技術研究センター研究開発助成

  Date (from‐to) : 2015/04 -2016/03 

  Author : 川﨑 了
• 自然に学ぶコンクリート構造物の新しい修復・保全技術の開発

  東日本高速道路：NEXCO東日本技術研究助成

  Date (from‐to) : 2015/01 -2015/12 

  Author : 川﨑 了
• 自己修復機能を持つ環境保全型保存材料の開発

  日本学術振興会：科学研究費補助金（基盤研究（Ｂ））

  Date (from‐to) : 2012/04 -2015/03 

  Author : 川﨑 了
• Research about the maintenance and replacement technique for the infrastructure by using microbes for the littoral region

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2011/04 -2014/03 

  Author : HATA Toshiro, KAWASAKI Satoru, KIKUCHI Yoshiaki, MORIKAWA Yoshiyuki, MIZUTANI Takaaki, KANEDA Kazuhiro

   

  In this study, a new management method for construction and maintenance technology based on microbial functions was developed. This method can be used to improve soil strength and in-situ water insulation control. This new method was applied and analyzed in a field survey using beachrock from Japan and Srilanka. Further, laboratory tests using artificial beachrock formation were carried out. Two main results arose from this study. First, it was found that calcium, magnesium, silica, and iron are acceptable as cement substances of beachrock. Further, calcite was found to be the most effective cement substance of beachrock originating from Kumejima Island, Japan, and Sri Lanka. Second, it was found that the bacterium Sporosarcina aquimarina, which is isolated from marine zones, is effective in improving soil strength and increasing soil liquefaction strength.
• Standardization of leaching, immobilization, and adsorption experiments for excavated rock samples

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2011/04 -2014/03 

  Author : IGARASHI Toshifumi, YONEDA Tetsuro, KAWASAKI Satoru, TAMOTO Shuichi

   

  Batch and column leaching experiments using mudstone samples were conducted to understand the leaching processes and mechanisms of arsenic, selenium, and boron. The results showed that two leaching mechanisms, consisting of a rapid leaching related to easily leachable fraction and a slower leaching related to pyrite oxidation, controlled the phenomena. The results of both batch and column leaching experiments can be explained by the two fractions. Batch and column adsorption experiments for the leached arsenic, selenium, and boron were carried out to elucidate the adsorption processes. The results showed that the leached arsenic, selenium, and boron were adsorbed by not only artificial adsorbents but also natural adsorbents like volcanic ashes when the pH did not change dramatically.
• Self-sealability of fractures in rock and its application to fracture and strength control

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2010/04 -2014/03 

  Author : KANEKO Katsuhiko, KAWASAKI Satoru, NARA Yoshitaka, ITO Mayumi, MUKUNOKI Toshifumi, HIROYOSHI Naoki, SAKAGUCHI Kiyotoshi, HARADA Syusaku

   

  A series of experimental studies on the sealability of fracture has been performed and its application to geotechnical engineering has been discussed. Firstly, analyzing the influence of environments on the sub-critical crack growth in rock, the mechanism of crack growth has been clarified. Secondarily, the self-sealing process of fracture in the rocklike material in water was investigated and the mechanism of self-sealing was clarified. Thirdly, the process of fracture propagation was analyzed numerically and a design method to control fracture propagation, i.e., crack orientation and so on. From these results, a method to estimate the long-term strength of rock has been proposed. Furthermore it is pointed out that the strength of rock can be controlled by controlling the environmental condition.
• ビーチロック形成機構に学ぶ新しい地盤固化技術の開発

  前田記念工学振興財団：平成24年度研究助成

  Date (from‐to) : 2012/04 -2013/03 

  Author : 川﨑 了
• ビーチロック形成機構に学ぶ新しい液状化対策技術に関する基礎的研究

  大林財団：平成23年度研究助成

  Date (from‐to) : 2012/04 -2013/03 

  Author : 川﨑 了
• シリカを用いた地盤のバイオ固化処理の有効性評価

  北海道ガス：大学研究支援制度

  Date (from‐to) : 2011/04 -2012/03 

  Author : 川﨑 了
• 微生物機能を利用した環境保全型保存材料の提案

  日本学術振興会：科学研究費補助金（基盤研究（Ｂ））

  Date (from‐to) : 2009/04 -2012/03 

  Author : 川﨑 了
• 微生物の代謝活動により固化する新しい保存材料の作製と評価

  日本学術振興会：科学研究費補助金（基盤研究（Ｂ））

  Date (from‐to) : 2006/04 -2009/03 

  Author : 川﨑 了
• Study on Micro-Restructuring of Rocklike Materials

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2007 -2009 

  Author : KANEKO Katsuhiko, TAKAHASHI Hiroshi, IGARASHI Toshifumi, SATO Tsutomu, MURATA Sumihiko, KAWASAKI Satoru, ITO Mayumi

   

  A series of experimental studies for the micro-restructuring of rocklike materials has been carried out. Various techniques to improve the physical properties of rocklike materials by reconstructing their microstructures have been developed, i.e., a method to change the rock strength by controlling of micro-cracking, a grout technique using microorganisms, a sealing technique using mineral separation from the ground water and so on.
• 寒冷地を想定した低温環境下におけるバイオグラウトの有効性評価

  北海道ガス：大学助成金

  Date (from‐to) : 2006/04 -2007/03 

  Author : 川﨑 了
• 微生物代謝により固化する新しいグラウトの開発に関する基礎的研究

  文部科学省：科学研究費補助金（萌芽研究）

  Date (from‐to) : 2005/04 -2007/03 

  Author : 川﨑 了
• Fracturing Design Method based on the Fractal Fracture Mechanics

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2004 -2006 

  Author : KANEKO Katsuhiko, HIRATA Atuo, TAKAHASHI Hiroshi, KAWASAKI Satoru, IGARASHI Tosifumii, KATO Masaji

   

  1. The application of a microscopic strength distribution and the fracture process zone can enable representation of the rock fracture process from micro-to macro-scales under an applied load. From these considerations, we proposed a fracture process analysis based on the Fractal Fracture Mechanics. In this analysis, the microscopic strength is modeled by Weibull' s distribution function and the inelastic behavior in the fracture process zone by a strength softening curve. The proposed fracture process analysis was perfomed for various applied pressures to investigate the influence of an applied pressure waveform on dynamic fracture process in rock. 2. From the results of the DT tests and crack path analysis, it was shown that the crack density and preferred orientation of the pre-existing microcracks affected the crack growth behavior. The difference between the activation energies of subcritical crack growth in rock are caused by the preferred orientation of the pre-existing microcracks. 3. A micro focus X-ray CT system was used to visualize the 3-dimensional microstructure of a rock specimen used in the dynamic tension test based on the Hopkinson's effect. Numerous cracks that do not coalesce to form a single fracture plane were observed and the multi-crack growth predicted by the Fractal Fracture Mechanics is confirmed. Furthermore, microstructures of Bentnite-Quartz Mixtures and Fiber-Cement-Stabilized Soils were observed and discussed
• Fragmentation controlled blasting

  Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research

  Date (from‐to) : 2002 -2003 

  Author : KANEKO Katsuhiko, TAKAHASHI Hiroshi, IGARASHI Tosifumii, OGATA Yuji, KATO Masaji, KAWASAKI Satoru

   

  (1) The dynamic fracture process in Hopkinson's test was analyzed using proposed finite element method to verify the strain-rate dependency of dynamic tensile strength. It is clarified that the strain-rate dependency is due to the stress concentration and redistribution mechanism in the rock. The rock inhomogenety also contributed to the strain-rate dependency. (2)The fracture process in one free-face rock was analyzed to investigate the fracture pattern and its mechanism. It was cleared that the fracture process as well as the fracture pattern were affected by the applied pressure-rate. The transition between quasi-static and dynamic fracture process can be estimated by the non-dimensional time defined by the propagation velocity, the burden and rise time of the applied pressure. (3)A numerical simulation method, coupled the finite element arid the finite difference calculation, to analyze the multiple fracture propagation due to stress waves and the detonation gas is developed. It is confirmed that the detonation gas considerably affects the generation and propagation of the fractures and that he numerical gas-propagation velocity along the fractures approximately agrees with that obtained by the laboratory experiments. It is concluded that the gas velocity along the fracture in bench blasting is lower than the air sound velocity except for the vicinity of the blast hole. (4)A method to predict the fragment size distribution in bench blasting using numerical and image analyses was proposed. In this method, the fracture process in bench blasting was analyzed using proposed FEM and fragment size distribution was evaluated by the image analysis of FEM result. (5)Rock fragmentation in bench blasting was examined using proposed method and the influence of blast condition on fragmentation was clarified. It is recognized that the widely spaced blast pattern is effective to reduce the bolder in fragments. Furthermore, it is pointed out that the optimal fragmentation in the field with respect to delay time depends strongly on the gas flow through the fractures caused by the stress wave.
• 簡易反発硬度試験による石造文化遺産の健全度調査手法の開発

  文部科学省：科学研究費補助金（奨励研究（Ａ））

  Date (from‐to) : 2000/04 -2002/03 

  Author : 川﨑 了
• 平成14年度少壮研究者による海外学術研究調査

  日本鉱業振興会：少壮研究者による海外科学技術研究調査助成

  Date (from‐to) : 2002 -2002 

  Author : 川﨑 了
• Fundamental Study on Novel Grout Cementing Due to Microbial Metabolism

  Date (from‐to) : 2001

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