MF研究者総覧

Researcher Database

Advance
Researchers' Page on researchmap
Last Updated :2024/10/08

Researcher Profile and Settings

Master

Affiliation (Master)

  • Faculty of Engineering　Sustainable Resources Engineering　Resources Engineering

Affiliation (Master)

  • Faculty of Engineering　Sustainable Resources Engineering　Resources Engineering

researchmap

Profile and Settings

Affiliation

  • Hokkaido University, Faculty of Engineering, Division of Sustainable Resources Engineering
  • Hokkaido University, School of Engineering, Department of Socio-Environmental Engineering

Degree

  • Ph.D.（2014/03 Hokkaido University）

Profile and Settings

  • Contact Point

    m_katoasahikawa-nct.ac.jp

  • Name (Japanese)

    Kato

  • Name (Kana)

    Masaji

Affiliation

  • Hokkaido University, Faculty of Engineering, Division of Sustainable Resources Engineering
  • Hokkaido University, School of Engineering, Department of Socio-Environmental Engineering

Achievement

Research Interests

  • Porous Media   Poroelasticity   Permeability Test   Rocks   Hydraulic Property   Geothermics   Geothermal Energy   Hydrogen Storage Alloy   X-ray CT   

Research Areas

  • Energy / Earth resource engineering, energy science / Natural Resources Development Engineering
  • Energy / Earth resource engineering, energy science / Rock Engineering
  • Energy / Earth resource engineering, energy science / Geothermal Engineering
  • Energy / Earth resource engineering, energy science / Geoinformatics

Research Experience

  • 2024/10 - Today National Institute of Technology, Asahikawa College Department of Mechanical Systems Engineering Associate Professor
  • 2024/10 - 2025/03 Hokkaido University Faculty of Engineering, Division of Sustainable Resources Engineering
  • 2024/10 - 2025/03 Hokkaido University School of Engineering, Department of Socio-Environmental Engineering
  • 2010/04 - 2024/09 Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University Assistant Professor
  • 2002/04 - 2020/03 The National Institute of Advanced Industrial Science and Technology (AIST) Cooperative Researcher
  • 2007/04 - 2010/03 Divisoin of Field Engineering for Environment, Graduate School of Engineering, Hokkaido University Assistant Professor
  • 2004/04 - 2007/03 Division of Field Engineering for Environment, Graduate School of Engineering, Hokkaido University Research Associate
  • 1997/04 - 2004/03 Division of Environment and Resources Engineering, Graduate School of Engineering, Hokkaido University Research Associate
  • 1993/04 - 1997/03 Department of Mineral Resources Development Engineering, Faculty of Engineering, Hokkaido University Research Associate

Committee Memberships

  • 2021/06 - Today   Japanese Society for Rock Mechanics   Representative
  • 2017/06 - Today   Japanese Society of Rock Mechanics   Secretary of Electric Journal committee
  • 2013/06 - Today   Japanese Society for Rock Mechanics   Associate Editor of Electronic Journal Committee
  • 2003/10 -2018/09   The Geothermal Research Society of Japan   Member of Planning Committee

Awards

  • 2020/05 一般社団法人岩の力学連合会 2019年度岩の力学連合会フロンティア賞
     含有する粘土鉱物の種類と構造に着目した岩質材料の力学特性評価 
    受賞者: 河野勝宣;奈良禎太;加藤昌治;西村強
  • 1999/06 Hokkaido Branch, Mining and Materials Processing Institute of Japan Special Award of the Hokkaido Branch Manager, Mining and Materials Processing Institute of Japan
     
    受賞者: Masaji Kato

Published Papers

  • Yoshitaka NARA, Koki KASHIWAYA, Kazuki OKETANI, Hirokazu FUJII, Yue ZHAO, Masaji KATO, Kazuhei AOYAGI, Yusuke OZAKI, Hiroya MATSUI, Masanori KOHNO
    Journal of the Society of Materials Science, Japan 73 (3) 220 - 225 2024/03 [Refereed]
  • Yoshitaka NARA, Masaji KATO, Tsutomu SATO, Masanori KOHNO, Toshinori SATO
    Journal of MMIJ 138 (4) 44 - 50 2022/04 [Refereed]
  • SAKEMOTO Kotone, KATO Masaji, ISHII Yusuke, KURUMISAWA Kiyofumi, NARA Yoshitaka
    Journal of the Society of Materials Science, Japan 公益社団法人 日本材料学会 71 (3) 228 - 234 0514-5163 2022/03/15 [Refereed][Not invited]
     
    Information on the permeability of materials for radioactive waste disposal in geological repositories is essential. High strength and ultra low permeability concrete (HSULPC) is being considered as a material used to package transuranic (TRU) waste. HSULPC would be reinforced by steel fiber to increase its tensile strength and toughness, but the effect of reinforcing steel fiber on permeability is unclear. Permeability tests need to be highly accurate to determine the hydraulic properties of low permeability materials. In this study, the hydraulic conductivity of HSULPC with steel fiber using the transient pulse method. The hydraulic conductivities of HSULPC with/without steel fiber were determined to be around 10−13 to 10−11 m/s under the confining pressures between 2 and 10 MPa and pore pressure of 1 MPa constant. The results further showed that the permeability of these materials had a hysteretic dependence on the effective confining pressure. There was no remarkable difference of hydraulic conductivity between HSULPC with and without steel fiber. SEM observation revealed that HSULPC with steel fiber has isolated voids to some extent included during mixing of concrete but there are few voids on the interface of steel fiber for water channel. However, due to the higher porosity, the hydraulic conductivity of HSULPC with steel fiber is relatively higher than that without fiber. Still, the permeability of fiber reinforced HSULPC is low enough compared with Horonobe mudstone and Toki granite and would enable it to effectively confine 14C radionuclides in TRU waste.
  • Kotone Sakemoto, Masaji Kato, Yusuke Ishii, Kiyofumi Kurumisawa, Yoshitaka Nara
    Materials Transactions 63 (12) 1639 - 1644 1345-9678 2022 [Refereed]
     
    Information on the water permeability of materials for radioactive waste disposal in geological repositories is essential. High strength and ultra-low permeability concrete (HSULPC) is being considered as a material used to package transuranic (TRU) waste. HSULPC would be reinforced by steel fiber to increase its tensile strength and toughness, but the effect of reinforcing steel fiber on permeability is unclear. Permeability tests need to be highly accurate to determine the hydraulic properties of low permeability materials. In this study, the hydraulic conductivity of HSULPC with steel fiber using the transient pulse method. The hydraulic conductivities of HSULPC with/without steel fiber were determined to be around 10113 to 10111 m/s under the confining pressures between 2 and 10 MPa and pore pressure of 1 MPa constant. The results further showed that the permeability of these materials had a hysteretic dependence on the effective confining pressure. There was no remarkable difference of hydraulic conductivity between HSULPC with and without steel fiber. SEM observation revealed that HSULPC with steel fiber has isolated voids to some extent included during mixing of concrete but there are few voids on the interface of steel fiber for water channel. However, due to the higher porosity, the hydraulic conductivity of HSULPC with steel fiber is relatively higher than that without fiber. Still, the permeability of fiber reinforced HSULPC is low enough compared with Horonobe mudstone and Toki granite and would enable it to
  • M. Kato, Y. Nara, D. Fukuda, M. Kohno, Toshinori Sato, Tsutomu Sato, M. Takahashi
    Journal of the Society of Materials Science, Japan 70 (4) 300 - 306 0514-5163 2021 [Refereed][Not invited]
     
    Because rock masses serve as natural barriers for geological disposal of radioactive waste, information about rock permeability is essential. An understanding of the influence of the surrounding environment temperature on the results is necessary for highly accurate permeability measurements. Herein we describe how to perform precise permeability measurements. Then, to investigate the influence of the surrounding environment temperature, we show the results of permeability measurements under conditions with dramatic changes using the transient pulse method and a Toki granite sample obtained from Gifu Prefecture in central Japan. The measured permeability without a temperature change is used as a reference. A change in the surrounding environment temperature remarkably affects the pressure in the upstream and downstream reservoirs, their pressure difference, and the confining pressure. An increase in the experimental system temperature increases the pressure. This difference is directly related to the estimated permeability. To accurately measure the rock permeability, it is essential to minimize changes in the surrounding environment temperature because they significantly affect the pressure difference.
  • Precise Permeability Measurement for High Strength and Ultra Low Permeability Concrete under Controlled Temperature
    Masaji KATO, Yoshitaka NARA, Kazutoshi SHIBUYA
    Zairyo 69 (3) 263 - 268 2020/03 [Refereed][Not invited]
  • Precise permeability measurement for high strength and ultra low permeability concrete under controlled temperature
    M. Kato, Y. Nara, K. Shibuya
    Materials Transactions 61 (11) 2134 - 2138 2020 [Refereed][Not invited]
  • Change of permeability in high-strength and ultra-low-permeability concrete in seawater
    Satoshi Maezaki, Yoshitaka Nara, Masaji Kato, Kazutoshi Shibuya
    5th ISRM Young Scholars' Symposium on Rock Mechanics and International Symposium on Rock Engineering for Innovative Future, YSRM 2019 971 - 976 2019 
    For geological disposal of radioactive wastes, the confinement of radionuclides is necessary. The geological disposal of radioactive waste is designed with a confinement function by suppressing the adsorption and migration of nuclides by natural and engineered barriers. However, long half-life low heat generating radioactive waste (TRU waste) contains wastes with a high concentration of nuclides that are difficult to adsorb on engineered and natural barriers. As an alternative method, long-term confinement with a waste package using High-Strength and Ultra-Low-Permeability Concrete (HSULPC) is considered so that a sufficient confinement function works even in such a case. It was shown that a macroscopic fracture in HSULPC in distilled water was sealed by the precipitation of calcium compounds. In artificial seawater, the precipitation of calcium compounds happened more significantly. However, none has not studied the permeability changes in HSULPC due to the fracture sealing by the precipitation of calcium compounds yet. In this study, we have conducted permeability measurements on a macro-fractured HSULPC. In particular, we kept the macro-fractured HSULPC specimen in an artificial seawater, and investigated the influence of calcium compound precipitation on hydraulic conductivity. It was shown that the introduction of macroscopic fracture increased the hydraulic conductivity. In addition, when the macro-fractured HSULPC was kept in artificial seawater, the fracture was filled partly by the precipitation of calcium compounds, which decreased the hydraulic conductivity. When HSULPC is put in the underground condition, the fracture closure in HSULPC can occur due to the existence of groundwater with high electrolyte concentration. Therefore, even if HSULPC is fractured, it is considered that self-healing of the fracture can occur, and the confining ability can be maintained for a long-term.
  • Effects of clay-mineral type and content on the hydraulic conductivity of bentonite-sand mixtures made of Kunigel bentonite from Japan
    M. Kohno, Y. Nara, M. Kato, T. Nishimura
    Clay Minerals 53 (4) 721 - 732 2018/12 [Refereed][Not invited]
  • Y. Yoshimura, K. Nakashima, M. Kato, K. Inoue, F. Okazaki, H. Soyama, S. 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.
  • Application of the transient pulse method to measure clay permeability
    M. Kato, Y. Nara, Y. Okazaki, M. Kohno, Toshinori Sato, Tsutomu Sato, M. Takahashi
    Materials Transactions 59 (9) 1427 - 1432 2018/09 [Refereed][Not invited]
    ダウンロード
  • Masaji Kato, Yoshitaka Nara, Yuki Okazaki, Masanori Kohno, Toshinori Sato, Tsutomu Sato, Manabu Takahashi
    Zairyo/Journal of the Society of Materials Science, Japan 67 (3) 318 - 323 1880-7488 2018/03/01 [Refereed][Not invited]
     
    To ensure the safe geological disposal of radioactive wastes, it is important to determine the permeability of clays. The transient pulse test is suitable to apply to the low permeability materials, because it takes relatively short term to determine the permeability. Usually we increase the upstream pore pressure in the measurement with the transient pulse test. However, it is impossible to determine the permeability of clay in this procedure because of the increase of pore pressure. Therefore, the transient pulse test has never been applied to the determination of permeability of clays. In this study, we tried to apply the transient pulse test to a clay obtained in Mizunami Underground Research Laboratory to determine the permeability with decreasing the downstream pore pressure. It was clarified that the transient pulse test with decreasing downstream pore pressure is appropriate from the measurement of granite. It was shown that the permeability of a clay was determined by the transient pulse test with decreasing the downstream pore pressure, which agreed with the permeability determined from the falling head test. The measurement time of the transient pulse test is much shorter than that of the falling head test. It is concluded that the transient pulse test is appropriate for the determination of the permeability of clays.
    ダウンロード
  • Yoshitaka Nara, Masaji Kato, Ryuhei Niri, Masanori Kohno, Toshinori Sato, Daisuke Fukuda, Tsutomu Sato, Manabu Takahashi
    Pure and Applied Geophysics 175 (3) 917 - 927 0033-4553 2018/03/01 [Refereed][Not invited]
     
    © 2017, Springer International Publishing AG. Information on the permeability of rock is essential for various geoengineering projects, such as geological disposal of radioactive wastes, hydrocarbon extraction, and natural hazard risk mitigation. It is especially important to investigate how fractures and pores influence the physical and transport properties of rock. Infiltration of groundwater through the damage zone fills fractures in granite with fine-grained minerals. However, the permeability of rock possessing a fracture naturally filled with fine-grained mineral grains has yet to be investigated. In this study, the permeabilities of granite samples, including a macro-fracture filled with clay and a mineral vein, are investigated. The permeability of granite with a fine-grained mineral vein agrees well with that of the intact sample, whereas the permeability of granite possessing a macro-fracture filled with clay is lower than that of the macro-fractured sample. The decrease in the permeability is due to the filling of fine-grained minerals and clay in the macro-fracture. It is concluded that the permeability of granite increases due to the existence of the fractures, but decreases upon filling them with fine-grained minerals.
    ダウンロード
  • Masaji Kato, Yoshitaka Nara, Daisuke Fukuda, Masanori Kohno, Toshinori Sato, Tsutomu Sato, Manabu Takahashi
    Zairyo/Journal of the Society of Materials Science, Japan 65 (7) 489 - 495 1880-7488 2016/07/01 [Refereed][Not invited]
     
    Rock masses serve a vital function as natural barriers for geological disposal of radioactive waste therefore, information on rock permeability is essential. Highly accurate measurement of permeability requires understanding of how temperature changes in the surrounding environment influence measurement results. We performed permeability measurement under conditions with dramatic changes of temperature in the surrounding environment to investigate the influence of such changes on the experimental results. Measurement of permeability with no temperature change was also conducted as reference. All measurements were conducted using the transient pulse method, and the sample material used was Toki granite obtained from Gifu Prefecture in central Japan. We found that temperature changes in the surrounding environment remarkably affected the pressure in reservoirs upstream and downstream, the pressure difference between them, and the confining pressure all increased when temperature increased for our experimental system. Notably, pressure difference was affected immediately. This difference directly relates to estimation of permeability. As temperature changes significantly affect pressure difference, it is essential to minimize temperature changes in the surrounding environment so as to achieve accurate measurement of rock permeability.
    ダウンロード
  • Minoru Sato, Masaji Kato, Manabu Takahashi
    MATERIALS TRANSACTIONS 57 (2) 112 - 118 1345-9678 2016/02 [Refereed][Not invited]
     
    The evaluation of hydraulic constants is generally one of the main components of reservoir engineering projects such as the development of radioactive waste disposal sites or the construction of underground CO2 storage. In the example presented here, flow pump experiments were conducted for the Horonobe mudstone to evaluate specific storage and hydraulic conductivity. The flow pump experiments were conducted with an effective confining pressure that gradually increased from 2 to 10 or 12 MPa, followed by a subsequent reduction to the initial value. The hydraulic conductivity in all cases was observed to decrease with increasing effective confining pressure in the specimens, and it did not recover to its initial value after unloading. In contrast, specific storage was observed to decrease in some specimens with increasing effective confining pressure; although this tendency was not significant in comparison to the trend observed concerning hydraulic conductivity. We therefore used theoretical analysis to calculate hydraulic constants and evaluate error ranges based on the nonlinear least-squares method. The error range value of specific storage is proposed to reduce with larger flow rates under the same confining pressures. The experimental results showed an almost linear pressure distribution from the upstream to downstream surfaces, and also showed a gradual increase in differential pressure with time in the flow pump method. Taking error ranges into account, the flow pump method is probably an easy approach for evaluating the specific storage of mudstone compared with other means of investigation that are currently available.
    ダウンロード
  • M. Takahashi, M. Kato, W. Lin, M. Sato
    Geological Society Engineering Geology Special Publication 27 (1) 207 - 215 0267-9914 2016 [Refereed][Not invited]
     
    Void space and permeability are two primary factors controlling the movement and storage of fluids in rock and sediments. To investigate fluid flow anisotropy in Berea sandstone, permeability was measured in three perpendicular directions under effective confining pressure as a function of pore pressure. Permeability anisotropy was observed slightly in the normal and in two parallel directions to the bedding planes. We introduced microfocus X-ray computed tomography (CT) as a non-destructive tool and the three-dimensional medial axis (3DMA) method to quantify the flow-relevant geometric properties of the voids structure. Using this apparatus and structure analysis software, we obtained the distributions of pore size, throat size and the number of connecting paths between two faces in an arbitrary region of Berea sandstone. Using these data, we also evaluated the number of connecting paths between two faces and tortuosity within an arbitrary region, and discussed the relationship between permeability anisotropy and voids geometry.
  • Manabu Takahashi, Naoki Takada, Minoru Sato, Masaji Kato, Dae Sung Cheon, Weiren Lin
    Proceedings of the 13th ISRM International Congress of Rock Mechanics, Montreal, Canada, May 2015 133  2015/05/10 [Refereed][Not invited]
     
    © 2015 by the Canadian Institute of Mining, Metallurgy & Petroleum and ISRM. The permeability and specific storage of rocks and sedimentary layers deep underground are critical parameters for issues related to the buried evaluation of natural gas and oil, CO2 aquifer storage, various kind of waste storage and so on. The Shirahama sandstone of the Wakayama prefecture, Kii peninsular in central Japan, consists mainly of quartz grains with no cracks and rock fragments that are aggregations of various kind of minerals. The quartz grains have an average size of about 150 micron. The pre-existing pore sizes were distributed dominantly at approximately 1 micron, and the total porosity was about 13%. During the hydrostatic compression test, we measured permeability of Shirahama sandstone by Transient Pulse test for three mutually perpendicular directions. Permeability of Shirahama sandstone remained fairly constant while increasing the effective confining pressure. Permeability anisotropy was observed slightly in the normal and two parallel directions to the bedding planes. We used micro focus X-ray CT with high resolution of 10 micron to visualize and measure the voids space information in Shirahama sandstone. Three-dimensional data were obtained in the intact and stressed sandstone simultaneously. Pore structures and grain boundaries were clearly distinguished. Pore closure and grain movement were clearly observed with increasing confining pressure. Micro focus X-ray CT is an effective tool to visualize and measure the geometrical information in rocks. Three-dimensional medial axis (3DMA) method was introduced to quantify the flow-relevant geometric properties of the voids structure in Shirahama sandstone using μfocus X-Ray CT data. The number of connecting path between two faces, tortuosity and the shortest path distribution within an arbitrary region of Shirahama sandstone specimen were analyzed. Geometrical information on the number of connecting path shows reasonable correlation between permeability anisotropy and mutually perpendicular directions normal and parallel to bedding planes. In addition, we introduced numerical simulation of fluid flow of pressurized Shirahama sandstone by LBM, to discuss the permeability change caused by pressurization on effective confining pressure. We obtained the detailed distributions of fluid pressure and fluid velocity in relatively narrow voids space more than 10 μm. It was confirmed that pressurization effect on permeability caused by the decrease of the connecting path and the shortest path between arbitrary faces, and then caused a complex condition on fluid pressure and fluid velocity.
  • Masaji Kato, Manabu Takahashi, Satoru Kawasaki, Katsuhiko Kaneko
    ENVIRONMENTAL GEOTECHNICS 2 (2) 104 - 117 2051-803X 2015/04 [Refereed][Not invited]
     
    X-ray computed tomography (CT) is useful for non-destructively visualising internal features of non-transparent objects. In addition, it provides quantitative information about the geometry and spatial distribution of an object's constituent materials. However, X-ray CT images include blurs and noises. Herein, the authors focus on the partial volume effect that causes blurs depending on image resolution. Artificial materials (e.g., thin wire and threads) and natural materials (e.g., oil sand) were observed using a microfocus X-ray CT scanner. A maximum likelihood thresholding method considering the partial volume effect based on histogram data was applied for segmenting two-and three-phase X-ray CT images. Relative errors in measured cross-sectional areas of aluminium wires and nylon threads were evaluated for verifying the segmentation method. Occupancy ratios of each phase of oil sand to its bulk volume were quantified. The introduced segmentation method estimates the volume of each constituent of two-and three-phase porous materials with reasonable accuracy.
    ダウンロード
  • A Study on Hydraulic and Poroelastic Properties of Low-Permeability Rocks
    KATO Masaji
    Hokkaido University 2014/03 [Refereed][Not invited]
    ダウンロード
  • Y. Kobayashi, S. Kawasaki, M. Kato, T. Mukunoki, K. Kaneko
    Advances in Computed Tomography for Geomaterials: GeoX 2010 287 - 294 2013/01/21 [Refereed][Not invited]
     
    This study evaluates the change in porosity of a biogrout specimen using micro-focus x-ray CT scanner and image processing. First, we selected the suitable geomaterials for evaluation of porosity. The results showed that glass beads whose particle size was 0.50-0.71mm were suitable. Second, we calculated the porosity of the glass beads using a method for evaluation of porosity based on a maximum likelihood thresholding method considering the effect of mixels, which are pixels having a two-phase structure. The result showed that the ratio of the porosity of grouted geomaterial to that of ungrouted one was 0.98-0.99, whereas 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 changes in porosity with great accuracy. © ISTE Ltd 2010.
  • M. Takahashi, W. Lin, M. Kato
    ROCK MECHANICS FOR RESOURCES, ENERGY AND ENVIRONMENT 347 - 350 2013 [Refereed][Not invited]
     
    The advantage of using centrifugal acceleration as a fluid driving force is that it acts as a body force in a way that is similar to that of gravity. To compare the saturated hydraulic conductivity of impermeable rocks, constant head tests under centrifugal acceleration and gravity, and Transient Pulse tests were conducted. Shirahama sandstone and Kabasan granite were used as specimens for determining the hydraulic conductivity. The centrifugal constant head method proved to be low hydraulic conductivity value by an order of 1 or 2 than that by the gravity Transient Pulse method. The reason was assumed to be that an unsaturated region occurred in the bottom of the specimen because the centrifugal force is greater near the bottom (downstream side) than the top of the specimen. To avoid unsaturation inaccuracies as much as possible, appropriate specimen length and sufficient water pond will be necessary for the loading bucket assembly.
  • 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.
  • Masaji Kato, Manabu Takahashi, Katsuhiko Kaneko
    Journal of MMIJ 資源・素材学会 129 (7) 472 - 478 1881-6118 2013 [Refereed][Not invited]
     
    The transient pulse method is suitable for measuring hydraulic constants of low-permeability rocks in the laboratory. This method is established and reliable; however, there is room for improvement. In this study, we examined analytical solutions of the transient pulse method and introduced a versatile technique of precise test data analysis with sensitivity analysis and experimental error estimation that is based on the nonlinear least-squares method and is applicable to other permeability tests. We also carried out highly precise transient pulse permeability tests in the laboratory and obtained highly precise experimental data. Based on the results, we validated our proposed data analysis technique based on nonlinear least squares. We conducted transient pulse permeability tests using Inada granite, which is a low-permeability rock, and evaluated its hydraulic constants (hydraulic conductivity and specific storage) using the exact solution of the transient pulse method. We estimated the experimental error between the analytical solution and the experimental data simultaneously. When the approximate solution is used, we can increase precision by considering the compressible storage of the upstream and downstream reservoirs and tubing, which is estimated by a calibration test, instead of considering only water compression. Sensitivity analysis revealed that the sensitivity of the hydraulic head difference between the upstream and downstream reservoirs in terms of hydraulic conductivity is an order of magnitude greater than that in terms of specific storage. This means that the relative error of hydraulic conductivity obtained in a laboratory test is an order of magnitude less than that of specific storage. In precise experiments, control of the room temperature is important because the fluids used in pore and confining lines have thermal expansion characteristics that are sensitive to temperature variation, and the differential pressure transducer is also directly affected by temperature change. The pressure pulse should be as small as possible because if a large change in pressure occurs, the effective stress state of the specimen changes and the permeability changes with it.
  • Masaji Kato, Manabu Takahashi, Katsuhiko Kaneko
    Journal of MMIJ 資源・素材学会 129 (7) 409 - 417 1881-6118 2013 [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 [Refereed][Not invited]
  • TAKAHASHI Manabu, KATO Masaji, TAKAHASHI Naoki, FUJII Yukiyasu, PARK Hyuck, TAKEMURA Takato
    応用地質 日本応用地質学会 53 (1) 31 - 42 0286-7737 2012/04/10 [Refereed][Not invited]
  • Three-dimensional pore distribution of Kimachi sandstone and its permeability and specific storage change by the effective confining pressure
    Manabu Takahashi, Masaji Kato, Yukiyasu Fujii, Naoki Takahashi, Park Hyuck, Minoru Sato
    ISRM International Symposium - EUROCK 2012 2012 
    Porosity and permeability are two primary factors controlling the movement and storage of fluids in rock and sediments. We measured permeability and specific storage of Kimachi sandstone for three perpendicular directions under effective confining pressure. In general, the permeability decreased with increasing the effective confining pressure. Permeability for X direction under low effective confining pressure is decreased dominantly, compared with others. On the other hand, specific storage for Z direction shows slightly low value and different tendency with increasing effective confining pressure. We introduced the three-dimensional medial axis (3DMA) method of Lindquist et al. (2000) to quantify the flow-relevant geometric properties of the voids structure in clastic sandstone. We verify the 3DMA method for application to clastic sandstone whose porosity is almost 20% and measure distributions of pore size, throat size, channel length, coordination number, and number of connecting path between two faces in arbitrary region of Kimachi sandstone specimen. In addition, we discuss the quantitative characterization of each distribution under intact and stressed to 25MPa of Kimachi sandstone.
  • YAMANAKA HIROSHI, KAWASAKI SATORU, KATO MASAJI, MUKUNOKI TOSHIFUMI, KANEKO KATSUHIKO
    Japanese Geotechnical Journal 6 (2) 273 - 284 1880-6341 2011/07 [Refereed][Not invited]
  • TAKAHASHI Manabu, KATO Masaji, URUSHIMATSU Yukihiko, PARK Hyuck
    Journal of the Japan Society of Engineering Geology 一般社団法人日本応用地質学会 50 (5) 280 - 288 0286-7737 2009/12 [Refereed][Not invited]
     
    To quantify the flow-relevant geometrical properties of the pore structure in Berea sandstone, we used the 3DMA method of LINDQUSIT et al. (2000) and verified three-dimensional data for different stress conditions obtained by micro focus X-ray CT. We showed the original CT data and an example of medial axis analysis for the packing of glass beads with 600μm diameters, and confirmed visually the accuracy of the medial axis analysis. We verified the geometric information between pore and throat, such as distributions of pore size, throat size, channel length, and coordination number, by the 3DMA method. In addition, we presented the quantitative characterization of each distribution for intact Berea sandstone and Berea sandstone pressurized to 25MPa.
  • KOBAYASHI Yuya, KAWASAKI Satoru, KATO Masaji, MUKUNOKI Toshifumi, KANEKO Katsuhiko
    Journal of MMIJ 社団法人 資源・素材学会 125 (10/11) 540 - 546 1881-6118 2009/11/25 [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 ...
  • TAKAHASHI Manabu, TAKEMURA Takato, KATO Masaji
    Journal of the Japan Society of Engineering Geology 45 (4) 192 - 196 0286-7737 2004/10 [Refereed][Not invited]
     
    To visualize the microstructure in rocks under confining pressure, micro focus X-ray CT system that can get three dimensional data simultaneously with high resolution of 10 micron is introduced. A new pressure vessel for micro focus X-ray CT that can be pressurized up to high confining pressure of lOOMPa is developed. Using this pressure vessel, the aperture changes of preexisting fracture in the fault related granite and in cored mudstone were observed. Aperture decreased firmly with increasing confining pressure. The multi planar reconstruction images enable us to distinguish well between...
  • G Dhakal, T Yoneda, M Kato, K Kaneko
    ENGINEERING GEOLOGY 65 (1) 31 - 45 0013-7952 2002/01 [Refereed][Not invited]
     
    Slake durability of rocks is an important property of rock-mass and rock-materials in geotechnical practice. The slake durability of rocks is closely related to their mineralogical composition. In this paper, mineralogical examinations and slake durability tests for argillaceous clastic rocks, especially pyroclastic rocks, sandstones and mudstones of Neogene Tertiary age from Japan, were performed in order to assess the slake durability and rock alteration process of these rocks as well as to understand the relationship between mineralogy and durability. The mineral composition and textural features of the rocks were studied by means of optical microscopy (OM), X-ray diffractometry (XRD), electron microprobe analysis (EPMA), and scanning electron microscopy (SEM). In addition, the slake durability test was carried out by using the standard testing method of ISRM [Int. J. Rock Mech. Min. Sci. 16 (1979) 148] in distilled water and in the aqueous solutions with dissolved electrolytes of NaCl and CaCl2. The pyroclastic rocks and tuffaceous sandstone, rich in di-octahedral and tri-octahedral Fe smectite, respectively, show distinctively different slaking behaviors. The pyroclastic rocks show relatively high slaking (Id(2) = 55.5% and Id(10) = 10.5%) than the tuffaceous sandstone (Id(2) = 94.1% and Id(10) = 87.8%, refer to text for Id(2) and Id(10)). This difference in the slake durability observed in these rocks is due to the microscopic occurrences of smectite present in the interspaces between the particles (pyroclastic rocks) and zeolite cementing the interspaces (tuffaceous sandstone) as alteration minerals. In addition, the durability results of tuffaceous sandstone show that the slake durability decreases as the degree of weathering increases (weathered material Id(2) = 88.7% and Id(10) = 65.3%). Furthermore, two mudstones of Miocene and Pliocene ages, having different clay mineral compositions (smectite vs. illite + chlorite), show the lowest and the highest slake durability among the tested clastic rocks. Hard mudstone shows the highest (Id(2) = 98.1% and Id(10) = 95.5%) while the soft mudstone shows the lowest (Id(2) = 33.9% and Id(6) = 0.4%.) slake durability. Thus, the slake durability of pyroclastic and sedimentary rocks is greatly affected by their mineral composition and texture, and is closely related to their alteration history. Slake durability is also affected by the kind of dissolved electrolyte and its concentration in the aqueous solution, providing some useful information for geotechnical practice. (C) 2002 Elsevier Science B.V. All rights reserved.
  • SH Cho, M Nishi, M Yamamoto, M Kato, K Kaneko
    PROCEEDINGS OF THE TWENTY-EIGHTH ANNUAL CONFERENCE ON EXPLOSIVES AND BLASTING TECHNIQUE, VOL I 187 - 196 2002 [Refereed][Not invited]
     
    This paper presents a numerical simulation method to predict rock fragmentation and to verify a fracture mechanism by bench blasting. The rock fragmentation, which has been used as a means of the index to estimate the effect of bench blasting, affects the expenses for loading, conveyance and crushing of blasting muck piles. The developed numerical simulation method is based on the finite element method and fracture mechanics and includes the re-meshing procedure to express the fracture process of the rock mass. This paper discusses a procedure for a determination of size distributions of the results, which were calculated by numerical simulation, including the fines.
  • KANEKO Katsuhiko, NAKAMURA Naoaki, OBARA Yuzo, ITO Kousuke, YONEDA Tetsuro, KATO Masaji
    Shigen-to-Sozai 社団法人 資源・素材学会,The Mining and Materials Processing Institute of Japan 116 (7) 572 - 576 0916-1740 2000/07 [Refereed][Not invited]
     
    A scheme to estimate the global stress state from the local stress state evaluated by the field stress measurement is proposed. In the scheme it is assumed that the global stress is expressed by the superposition of the stress induced by the gravity and that by the horizontal movement of the upper crust. The local stress state in the rock mass under the pit of Torigata-yama open cut mine, located in Shikoku Island, Japan, was measured by the Conical-Ended Borehole Technique. The local stress distribution in Mt. Torigata region was evaluated by the 3-dim. FE-analysis and the global strain an...
  • KATO Masaji, KAWAKAMI Yoshiki, YONEDA Tetsuro, KANEKO Katsuhiko, WADA Yuji, OGATA Yuji, KATSUYAMA Kunihisa
    Journal of the Japan Explosives Society 火薬学会 60 (5) 240 - 249 1340-2781 1999/10/31 [Refereed][Not invited]
  • Mineralogical characterization of rock weathering :Compositional and textural analyses of weathered rocks
    Yoneda,T. Dhakal, G.P, Kato,M, Kaneko,K
    Proc．’99 Japan-Korea Joint Sympo．Rock Eng. 381 - 386 1999/07 [Refereed][Not invited]
  • KATO Masaji, KOIKE Katsuaki, YONEDA Tetsuro, KANEKO Katsuhiko
    Shigen-to-Sozai 社団法人 資源・素材学会 114 (12) 909 - 917 0916-1740 1998/11 [Refereed][Not invited]
     
    Physical properties of rock, such as strength, elastic wave velocities and permeability, depend largely on microcrack geometry. In particular, anisotropy of these properties is intimately related to the distribution of microcrack orientations. In this paper, an estimating method for three-dimensional distribution of microcrack orientations in rock is introduced by using the associated Legendre function. If a microcrack is expressed by a penny shaped disk, the distributions of crack orientations and diameters are expressed using probability density functions respectively and the intersection...
  • KAGOTA Hisakazu, TOMINAGA Yuusaku, KATO Masaji, OHGA Kotaro, ONO Shuji, SATO Juichi, KOUDA Ryoichi
    Geoinformatics 日本情報地質学会 9 (2) 57 - 63 0388-502X 1998/06 [Refereed][Not invited]
     
    We considered fitting the lineaments to the set of the points extracted from the picture which expressed the geographical structures. In the case when a coefficient of linear equation which expresses the lineament is calculated by the method of least square for distance between the points and a straight line, the fittings among the linear equations of each sets of points can be compared by the averages of the residual sum of squares. In this paper, all points are expressed on a plane coordinates and objective variable y is expressed by the function f(x). When the coefficient of f(x)to minim...
  • TOMINAGA Yuusaku, TAKADA Naohide, KOUDA Ryouichi, KATO Masaji, ONO Shuji, OHGA Kotaro, TANAKA Takeshi
    Geoinformatics 日本情報地質学会 7 (3) 209 - 214 0388-502X 1996/09/25 [Refereed][Not invited]
  • Application of Geologic Information to Isothermal Mapping
    M. Kato, Y. Tominaga, K. Ohga, S. Ono, T. Tanaka
    Geoinformatics 7 (1-2) 13 - 18 1996/07 [Refereed][Not invited]
  • TANAKA TAKESHI, KATO MASAJI, TOMINAGA YUSAKU
    Hokkaido Geotechnics (7) 107 - 112 0915-6968 1996/02 [Refereed][Not invited]
  • Tanaka Takeshi, Kato Masaji, Yominaga Yuusaku
    Journal of the Japan Society of Engineering Geology 一般社団法人日本応用地質学会 34 (6) 284 - 291 0286-7737 1994/02/10 [Refereed][Not invited]
     
    Presently in the fields of civil engineering and resources development engineering, it is an important theme to grasp precisely existence of underground fractures or sheared faults. In development of geothermal resource, it is neccesary to estimate mechanism of heat and water supply in a wide area, and scale and shape of a geothermal reservoir in the area. In order to estimate potentiality of geothermal energy as hydrothermal convection system, it is important to know permeability of the geothermal reservoir. In the case of a fracture-type geothermal reservoir, existence of fracture system ...

MISC

Books etc

  • Developments in Engineering Geology
    M. Takahashi, M. Kato, W. Lin, M. Sato (Joint workThree-dimensional pore geometry and permeability anisotropy of Berea sandstone under hydrostatic pressure: connecting path and tortuosity data obtained by microfocus X-ray CT)
    Geological Society 2016

Teaching Experience

  • Applied MathematicsApplied Mathematics Hokkaido University

Association Memberships

  • International Geothermal Association   International Society for Rock Mechanics   Japanese Committee for Rock Mechanics   JAPANESE ASSOCIATION OF GROUNDWATER HYDROLOGY   JAPAN SOCIETY OF ENGINEERING GEOLOGY   JAPAN SOCIETY OF GEOINFORMATICS   THE GEOTHERMAL RESEARCH SOCIETY OF JAPAN   THE MINING AND MATERIALS PROCESSING INSTITUTE OF JAPAN   

Research Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2012/04 -2014/03 
    Author : KATO Masaji
     
    The autonomous metal hydride actuator developed in this study is a new energy conversion device of the future model that realize zero running cost and zero emission substantially. Its great advantage is that it can efficiently obtain mechanical and electric power using low-enthalpy hot spring heat less than 100 degrees Celsius in temperature.
  • Geothermal utilization technique using metal hydride actuator
    Date (from‐to) : 2007
  • 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
  • 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.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2001 
    Author : KANEKO Katsuhiko, KATO Masaji, OBARA Yuzo, YONEDA Tetsuro, NOGUCHI Yoshifumi
     
    Stability monitoring of rock slope is important for safety working of open cut mine. In this research project, a monitoring system of rock slope stability by the use of high sensitive tiltmeters has been proposed. (1) High sensitive tiltmeters were installed in a limestone mine and long term measurement has been performed. Analyzing the time series of tilt in rock mass, it is clarified that the cover rock of the slope is moving to downward and this moving is caused by the frictional sliding on the geological discontinuity between cover rock and base rock. From this result, it is confirmed that high sensitive tiltmeter is useful to monitor the rock slope stability. (2) A method to estimate the elastic moduli of rock mass using the earth moving as loading source has been proposed. By applying it to Shiriya mine, Young modulus and Poiison's ratio of rock mass in the present field were estimated to be lOGPa and 0.1, respectively. (3) A scheme to estimate the global stress state from the local stress state evaluated by the field stress measurement has been proposed. By applying it to Torigatayama mine, it is made clear that, in this region, the stress state induced by the horizontal movement of the upper crust is nearly uniaxial compression.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2001 
    Author : KANEKO Katsuhiko, TAKAHASI Hiroshi, HIRATA Atsuo, YONEDA Tetsuro, KATO Masaji
     
    Although the rock is generally considered to be a heterogeneous material, the rock is usually treated as a homogeneous material in the fracture mechanics. In this study, the influence of heterogeneity on the crack growth in rock was analyzed and discussed. (1) Double-Torsion test was performed to investigate the anisotropy of subcritical crack growth behavior in granite that is a typically heterogeneous rock. The experimental results confirmed that subcritical crack growth in granite was anisotropic and depended on the direction of the crack growth. Furthermore, the geometry of crack path becomes smoother in the case that the crack propagates with lower stress level. These behavior and characteristics are caused by the oriented microcracks. From these results, it is concluded that the crack growth in heterogeneous rock takes place with lower fracture energy by linking of mierocracks existing nearby crack tip. (2) Mineralogical examination, physical properties measurement and slake durability tests of some argillaceous clastic rocks have been carried out and it was made clear that the mineral composition and texture of rocks in addition to smectite mineralogy have a great influence in rock durability. (3) A numerical simulation method based on the finite element method and fracture mechanics for heterogeneous rock was proposed. Analyzing fracture processes of rock splitting by the breaker and rock fragmentation in bench blasting, the mechanism of splitting and fragmentation were clarified.
  • 堆積岩の変形・透水挙動の連成解析
    Date (from‐to) : 2001
  • Coupling analysis of deformation and pore fluid transport behaviors of sedimentary rocks
    Date (from‐to) : 2001
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1998 -1999 
    Author : KANEKO Katsuhiko, KATO Masaji, FUJII Yoshiaki, ASAKURA Kuniomi, YAMAMOTO Masaaki, HIRATA Atsuo
     
    The smooth blasting is a controlled blasting widely used in rock tunnel and cavern excavations. In this research project, the fracture process of rock in the smooth blasting has been analyzed and the key factors for improving and optimizing the smooth blasting is made clear. (1) A computer program to simulate the dynamic crack propagation in rock has been developed. Using this code, the rock fracture process in smooth blasting was analyzed and the influence of initiation time accuracy on the fracture process was clarified. (2) Comparing the crack propagation processes in static and dynamic loading, a relation between the dynamic strength and the static one of rock is made clear. Especially, it is pointed out that heterogeneity of micro-scale strength results in the difference of dynamic and static strengths. (3) The Compact Vertical Seismic Prospecting (CVSP) system to inspect the damaged are in the rock around cavern was developed. From the field measurement, it is confirmed that the CVSP system is useful to evaluate the depth of damaged zone around the tunnel. From these results, it is concluded that the high accurate initiation system and CVSP system are useful tool for optimization of the smooth blasting.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 1997 -1998 
    Author : 加藤 昌治
     
    自然対流型地熱資源の可採量評価に欠かせない断裂系の定量評価を目的として、自然対流系の形成に寄与するき裂と地熱開発に必要とされるき裂という異なったスケールの断裂系を取り上げ、いくつかの視点からそれらの評価をおこなった。本研究の内容と得られた成果は以下のようである。 蛍光浸透法により岩石端面で観察されるき裂トレースを画像データとして取り込み、画像処理を施した後、その幾何要素を統計確率的に抽出・評価した。その結果から岩石内のクランクの3次元分布特性(密度、方位、長さ、開口幅)を評価し、それから岩石の透水テンソルを求めた。本研究では、き裂分布特性評価と同時に岩石コアを用いた透水試験も実施し、その透水異方性を明らかにした。最終的に、求められた透水テンソルと透水試験結果との間には強い相関がみられた。 ある地熱地域において坑井掘削時に得られた逸泥データを地球統計学的に処理した。その結果、人間の生産活動的時間でみた貯留層の透水特性は、その分布に層状の片寄りのあることがわかった。したがって、地熱開発において熱水・蒸気のフィードポイントに坑井を到達させるためには、貯留層内のき裂密度の層状アノマリーに注意が必要である。 ある地熱地域の熱水系評価に有限要素法による2次元数値シミュレーションを実施した。現在の熱水系の状態を定常状態と仮定して、き裂性媒体である貯留層を等価多孔質体とみなし、その透水性としてボーリングコアの観察結果から低い浸透率を与えた。また、飽和岩石の熱物性値は、岩種と温度依存性を考慮して与えている。その結果として得られた温度分布は、実際に現地でおこなわれた温度検層の結果と良い一致を示した。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1996 -1997 
    Author : KANEKO Katsuhiko, KATO Masaji, FUJII Yoshiaki, MUNEKATA Mizue, KOIKE Katsuaki
     
    A series of experimental and theoretical investigation for the three dimensional visualization of rock fracturing process has been carried out. Results obtained are as follows. (1) The visualization of the fracture under various circumstances and loading conditions has been performed. It is clarified that the fracture process of granite under uniaxial compression is characterized by the crack propagation with complex modes. And it is confirmed that the failure process of rock splitting can be interpreted as the development of the process zone in front of the crack tip. (2) It is confirmed that X-ray CT method is effective to measure the aperture of open cracks and fluid migration in rocks. (3) The fragmentation process of rock was analyzed by FEM with taking into account the crack propagation and the heterogeneity of strength. It is made clear that the localization process is strongly affected by the strength heterogeneity. (4) The spatial distribution of attributes of rock joints has been analyzedy geomathematical methods. It was pointed out that the visualization of rock joint distribution is useful to evaluate the seepage flow in rock mass.
  • 多孔体の水理特性の評価のための透水試験法の高度化
    Date (from‐to) : 1997
  • Sophistication of permeability test methods for evaluating hydraulic properties of porous media
    Date (from‐to) : 1997

Industrial Property Rights

  • 特願2015-065157:地下熱交換装置及び地下熱利用システム  2015年/03/26
    佐藤圭介, 加藤昌治

Copyright © MEDIA FUSION Co.,Ltd. All rights reserved.