研究者データベース

石川 達也(イシカワ タツヤ)
工学研究院 土木工学部門 自然災害適応
教授

基本情報

所属

  • 工学研究院 土木工学部門 自然災害適応

職名

  • 教授

学位

  • 博士(工学)(京都大学)

ホームページURL

科研費研究者番号

  • 60359479

J-Global ID

研究キーワード

  • 地盤工学   数値解析   土砂災害   防災   舗装工学   積雪寒冷地   礫質土   交通荷重   主応力軸回転   繰返しせん断   凍結融解   路盤   環境技術   凍上   地球温暖化ガス排出削減   粒状構造物   繰返し塑性   主応力回転   路盤・路床   気候変動   鉄道   礫材   天然ガス   維持管理工学   不飽和土   せん断試験   自然災害   水工水理学   移動荷重   斜面崩壊   粒子破砕   火山灰質土   凍結・融解作用   地盤防災   室内要素試験   寒冷地地盤防災工学   Geotechnical Engineering(5203)   

研究分野

  • 社会基盤(土木・建築・防災) / 地盤工学
  • 社会基盤(土木・建築・防災) / 防災工学
  • 社会基盤(土木・建築・防災) / 地盤工学

職歴

  • 2019年04月 - 現在 北海道大学 大学院工学研究院 教授
  • 2017年04月 - 2019年03月 北海道大学 大学院公共政策学連携研究部 教授
  • 2013年10月 - 2017年03月 北海道大学 大学院工学研究院 教授
  • 2010年04月 - 2013年09月 北海道大学 大学院工学研究院 准教授
  • 2007年04月 - 2010年03月 北海道大学 大学院工学研究科 准教授
  • 2002年10月 - 2007年03月 北海道大学 大学院工学研究科 助教授

所属学協会

  • 日本自然災害学会   (社)地盤工学会   日本計算工学会   岩の力学連合会   ISSMGE   (社)土木学会   ISRM   日本地すべり学会   IACM   

研究活動情報

論文

  • Tianshu Lin, Tatsuya Ishikawa, Bin Luo
    Transportation Research Record 2673 3 439 - 449 2019年03月01日 [査読有り][通常論文]
     
    © National Academy of Sciences: Transportation Research Board 2019. This paper proposes a modified University of Illinois at Urbana–Champaign (UIUC) model to predict permanent deformation behavior of unbound aggregate materials. Most existing models relate permanent deformation to resilient properties, whereas the UIUC model treats shear strength as a critical factor in permanent deformation behavior. Three types of test, monotonic shearing test, cyclic axial loading test, and cyclic axial and shear loading test, were conducted by multi-ring shear apparatus on two kinds of parallel grading aggregate materials, natural crusher-run and recycled crusher-run obtained from demolished concrete structure. Test results demonstrate that shear strength is the core factor in permanent deformation behavior, compared with resilient properties, and principal stress axis rotation (PSAR) greatly increases the permanent deformation. By considering the effect of PSAR on permanent deformation, a new parameter, (Rs)ave, is added to the conventional UIUC model to modify it. Regression analysis results verify that the modified UIUC model has good applicability for predicting permanent deformation of aggregates with different water contents and stress states, and with and without PSAR. The modified UIUC model builds a relation between test results with and without PSAR. A simple framework is also proposed for predicting permanent deformation in flexible pavement structures based on the modified UIUC model.
  • Tatsuya Ishikawa, Tianshu Lin, Jiaqiang Yang, Tetsuya Tokoro, Erol Tutumluer
    Transportation Geotechnics 18 149 - 162 2019年03月01日 [査読有り][通常論文]
     
    © 2018 Elsevier Ltd The main objective of this study is to evaluate the practicality of the UIUC model to the Japanese design standard for ballasted tracks of aged lines as well as of new lines by considering some uncertain effects which are not verified and incorporated in the UIUC model, like the effects of ballast fouling, fluctuation in moisture content, and principal stress axis rotation. For this reason, in this study, first the trends in the permanent deformation accumulation of ballasts with various moisture contents and fine fraction contents under moving wheel loads were examined based on the results of advanced laboratory element tests such as triaxial compression tests on unsaturated ballasts and multi-ring shear tests on ballasts under moving wheel loads. Next, the applicability of the UIUC models to the estimation of the permanent deformation accumulation of ballasts were verified by considering the influences of fine fraction content, moisture content, and principal stress axis rotation, and a modification method of the UIUC model necessary for improving the prediction precision and extending the applicability was proposed.
  • Subramanian Srikrishnan Siva, Ishikawa Tatsuya, Tokoro Tetsuya
    SOILS AND FOUNDATIONS 58 3 582 - 601 2018年06月 [査読有り][通常論文]
  • Thanh Binh Nguyen, Tatsuya Ishikawa, Srikrishnan Siva Subramanian
    PANAM UNSATURATED SOILS 2017: FUNDAMENTALS 301 135 - 145 2018年 [査読有り][通常論文]
  • Luo Bin, Ishikawa Tatsuya, Tokoro Tetsuya
    PROCEEDINGS OF GEOSHANGHAI 2018 INTERNATIONAL CONFERENCE: MULTI-PHYSICS PROCESSES IN SOIL MECHANICS AND ADVANCES IN GEOTECHNICAL TESTING 315 - 324 2018年 [査読有り][通常論文]
  • Luo Bin, Lai Hao, Ishikawa Tatsuya, Tokoro Tetsuya
    SCIENCES IN COLD AND ARID REGIONS 9 3 229 - 235 2017年06月 [査読有り][通常論文]
  • Biyanvilage Dareeju, Chaminda Gallage, Tatsuya Ishikawa, Manicka Dhanasekar
    SOILS AND FOUNDATIONS 57 3 423 - 438 2017年06月 [査読有り][通常論文]
     
    The cumulative plastic deformation of rail track subgrade materials under moving wheel loads is a complex problem. The plastic deformation and resilient modulus of subgrade materials subjected to moving wheel loads are a function of Principal Stress Axis Rotation (PSAR). Difficulties associated with the control of PSAR in conservative experimental methods lead to inaccurate estimations of the actual plastic deformation characteristics of rail track subgrade. Therefore, this study modifies a torsional multi-ring shear apparatus to evaluate the deformation characteristics of subgrade materials under moving wheel loads. The performance of this modified apparatus is evaluated by comparing the experimental results with those of small-scale model tests on an asphalt roadbed rail track with sandy subgrade. The evaluation suggests that the modified multi-ring shear apparatus has an excellent capability to estimate the deformation characteristics of rail track subgrade under moving wheel loads. A series of modified multi-ring shear tests is then conducted to investigate the effects of the loading conditions, the subgrade density, and the loading frequency on the deformation of subgrade materials under moving wheel loads. The results of these tests show that cyclic single-point load tests underestimate the actual deformation characteristics of subgrade materials irrespective of the subgrade density and the loading frequency. Furthermore, the ratio between the plastic cumulative deformations obtained from the moving wheel loading and from the cyclic single-point loading, referred to as the "ratio of axial strain" (Rs), is introduced to evaluate the plastic deformation characteristics of rail track subgrade materials under moving wheel loads only, using the results of cyclic single-point loading tests. Finally, an empirical formula is proposed to predict the cyclic plastic deformation of rail track subgrade materials as a function of the number of loading cycles. (C) 2017 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society. This is an open access article under the CC BY-NC-ND license.
  • Srikrishnan Siva Subramanian, Tatsuya Ishikawa, Tetsuya Tokoro
    ENGINEERING GEOLOGY 221 154 - 169 2017年04月 [査読有り][通常論文]
     
    In Hokkaido Japan, soil slope failures along some of the national highways are reported frequently in recent years. A stability assessment method which can consider the impact of seasonal changes like freeze-thaw action, snow melt water infiltration etc. is of utmost importance and considered to be an immediate requirement for geotechnical practitioners, in order to properly predict the slope stability. In this study, a slope stability assessment approach based on two-dimensional numerical modelling is recommended which considers the water content changes of the soil induced by the seasonal climatic effects i.e. freeze-thaw action, snowmelt water infiltration etc. Two case studies of slope failures in Hokkaido have been studied using the recommended approach. In order to visualise the climatic parameters of most influence on slope stability, parametric studies have been performed through which many useful results in view of the soil slope stability in seasonal cold regions have been obtained. It is found that the freeze-thaw action has a considerable impact on the soil water content and slope stability. On the other hand, the snowmelt water infiltration has a very significant impact on soil slope stability. The recommended numerical modelling approach is found to be very useful in analysing the soil slope stability in seasonal cold regions. (C) 2017 Elsevier B.V. All rights reserved.
  • 細田 充, 田中 博文, 石川 達也
    構造工学論文集. A A 63 171 - 181 土木学会 ; 2007- 2017年03月 [査読無し][通常論文]
  • Bin Luo, Tatsuya Ishikawa, Tetsuya Tokoro, Hao Lai
    TRANSPORTATION RESEARCH RECORD 2656 2656 12 - 22 2017年 [査読有り][通常論文]
     
    Evaluation of frost heave is essential for good design of a geotechnical structure in cold regions. Frost heave often causes severe roughness and cracking of structures like pavements. To model frost heave around a box culvert, a practical coupled thermo-hydro-mechanical (THM) model is presented. The performance of the proposed THM model, which can predict the freeze-thaw behavior of unsaturated soil, is demonstrated through frost heave tests under different conditions. A pavement structure located above a box culvert was simulated, and the analysis could reproduce phenomena observed in the field, including uneven upheave of the pavement and frost-heaving force induced by frost-susceptible backfill. To mitigate such damages, the mechanism and countermeasure of uneven frost heave were investigated. It was revealed that the freeze-thaw action considerably affects smoothness and failure of the pavement structure. In addition, the use of insulation may reduce roughness and extend the fatigue life of the pavement structure. The findings of this study are useful for minimizing frost heave in geotechnical structures.
  • 廣瀬剛, 伊藤譲, 石川達也, 赤川敏
    土木学会論文集 C(地圏工学)(Web) 73 2 131‐140(J‐STAGE)  2017年 [査読無し][通常論文]
  • Tetsuya Tokoro, Tatsuya Ishikawa, Shoya Shirai, Tsutomu Nakamura
    SOILS AND FOUNDATIONS 56 5 927 - 936 2016年10月 [査読有り][通常論文]
     
    This study estimates the water dependence of the thermal conductivity of soils and proposes a new thermal conductivity model and empirical equation for soil. Thermal conductivity tests for three different soil types were conducted under different moisture contents using the thermal probe method. Electrical conductivity tests were also performed to obtain the electrical resistibilities of the soils, and the influence of the moisture content on thermal conductivity was examined using the electrical conductivity data. The results show that the water dependence of thermal conductivity strongly correlates to the electrical resistibility. The relationships between the moisture contents and the thermal conductivities of the three soil types are found to be nonlinear, with an inflection point in each relationship. The moisture contents corresponding to these inflection points approximately agree with each other. The provision of a current flow largely along the pore water indicates that the thermal conductivity of a soil depends on whether or not the pore water, which significantly contributes to heat conduction, is continuous. The presence of pore water in soils can explain the water dependence of thermal conductivity. This study further proposes a model to estimate the thermal conductivity of soil and an empirical equation based on electrical conductivity test results. (C) 2016 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.
  • Tatsuya Ishikawa, Tetsuya Tokoro, Seiichi Miura
    SOILS AND FOUNDATIONS 56 5 790 - 804 2016年10月 [査読有り][通常論文]
     
    The aim of this study is to evaluate the effects of freeze thaw action on the water retention permeability characteristics of volcanic coarse grained soils under unsaturated conditions in order to examine the hydraulic behavior of volcanic soil during the snow-melting season. In this study, a series of water retention, permeability, and slaking tests on three types of crushable volcanic coarse-grained soils, differing in their degrees of particle crushability, were performed under various degrees of saturation and freeze thaw histories, while comparing the test results with those of non-crushable sand. Based on the experimental results, the effects of freeze thaw action on the water retentivity, permeability, and particle breakage were examined. The test results indicated that freeze thaw action has a strong influence on the hydraulic behavior of crushable volcanic coarse-grained soils under unsaturated conditions, even if the soil is a non-frost-susceptible geomaterial. (C) 2016 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V.
  • Tatsuya Ishikawa, Shinichiro Kawabata
    Innovative and Sustainable Solutions in Asphalt Pavements 262 77 - 85 2016年 [査読有り][通常論文]
     
    This paper examines the effects of freeze-thaw and water content on the mechanical behavior of granular base by performing model tests of granular roadbed and CBR tests of base course materials. We also evaluate the influences of the change in the performance of granular base on the fatigue life of pavement structures in cold regions by applying the theoretical design method for asphalt pavement in consideration of the effects found in the above-mentioned experiments. As the results, it was revealed that the bearing capacity of granular base increases in freezing season and decreases in thawing season. This indicates that the freeze-thaw of granular base has a strong influence on the fatigue life of pavement structures in cold regions because it varies the deformation-strength characteristics of base course materials.
  • Tatsuya Ishikawa, Shinji Fuku, Takahisa Nakamura, Yoshitsugu Momoya, Tetsuya Tokoro
    ADVANCES IN TRANSPORTATION GEOTECHNICS III 143 268 - 275 2016年 [査読有り][通常論文]
     
    This paper evaluates the synergistic effects of water content and fine fraction on shear behavior of unsaturated fouled ballast by performing a series of triaxial compression tests and water retention tests on fresh and fouled ballasts in unsaturated conditions. As the results, it was revealed that soil-water characteristic curves and relationships between degree of saturation and peak shear strength were seriously affected by intrusion of fouling materials into fresh ballast, and that the decreasing trend of peak strength becomes more remarkable in such a case where both water content and fine fraction increase. These results indicate that for the precise prediction of the long-term performance of transportation infrastructures and the evaluation for mechanical property of railroad ballast under repeated train passages, it is important to take into account the synergistic effects of water content and fine fraction on the deformation-strength characteristics of ballast in accordance with the degree of ballast fouling.
  • Shinichiro Kawabata, Tatsuya Ishikawa, Shuichi Kameyama
    ADVANCES IN TRANSPORTATION GEOTECHNICS III 143 828 - 835 2016年 [査読有り][通常論文]
     
    We used a newly developed freeze thaw California bearing ratio (CBR) test apparatus to investigate the effects of freeze thaw history on the bearing capacity characteristics of granular base course material. It was found that CBR was reduced by freeze-thaw under all water content conditions. Taking the example of C-40, which is frequently used as a base course material, freeze thaw cycles reduced CBR to about 0.6 times its initial value. We found volume expansion in even non-frost susceptible C-40, and therefore investigated changes in particle pore water due to freeze thaw cycles. We found that freezing causes particle pore water to be dislocated to particle surfaces, thereby causing interparticle friction and altering the void structure.
  • 石川 達也, 松谷 真吾, 所 哲也, 中村 貴久, 桃谷 尚嗣
    土木学会論文集E1(舗装工学) 72 3 I_151 - I_158 公益社団法人 土木学会 2016年 [査読無し][通常論文]
     
    本研究は,バラスト道床の合理的な維持管理方法の確立に寄与するため,中型不飽和三軸試験機を用いて,新品道床バラストと経年劣化を想定した細粒土混入道床バラストの単調載荷・繰返し載荷三軸圧縮試験と保水性試験を実施し,含水状態の違いが細粒化した道床バラストの強度・変形特性に及ぼす影響について検討した.その結果,道床バラストは細粒化によりその保水性が著しく高まること,および細粒分の有無や含水状態の違いが道床バラストの強度特性・繰返し塑性変形特性に強い影響を及ぼすことが明らかとなった.したがって,列車荷重繰返し載荷時のバラスト道床の挙動予測や道床バラストの長期性能評価を精度よく行うには,道床バラストの力学特性に対する細粒分増加と含水比変化との相乗効果を十分考慮する必要がある.
  • Tatsuya Ishikawa, Seiichi Miura
    SOILS AND FOUNDATIONS 55 2 242 - 257 2015年04月 [査読有り][通常論文]
     
    This paper presents an experimental study to evaluate the synergistic effects of principal stress axis rotation and change in water content on the mechanical behavior of granular roadbed subjected to cyclic moving wheel loads. Two types of small scale model tests and laboratory element tests, in which a single-point loading method and a moving-wheel loading method were adopted, were mainly performed with a base course material under air-dried condition and saturated condition. Based on the test results, the applicability of a multi-ring shear test, which is a torsional simple shear test, to an element test of granular base course materials subjected to moving wheel loads, and the influence of water content and moving-wheel loads on the deformation strength characteristics of granular roadbed were examined. The results indicate that the multi-ring shear test has excellent applicability to the estimation of deformation behavior of granular base course materials subjected to repeated moving-wheel loads. Besides, it was revealed that residual settlement of submerged granular roadbed is more likely to increase with the repetition of moving-wheel loads than that of air-dried one and under single-point loading, showing that the difference in the loading method and water content has a considerable influence on the cyclic plastic deformation of granular roadbed. These lead to the conclusion that for the precise prediction of the long-term performance of granular roadbed under cyclic moving-wheel loads, it is important to take into account the synergistic effects of principal stress axis rotation and change in water content on the cyclic plastic deformation characteristics of granular base course materials. (C) 2015 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.
  • 石川 達也, 木次谷 一平, 所 哲也
    土木学会論文集E1(舗装工学) 71 3 I_185 - I_192 公益社団法人 土木学会 2015年 [査読無し][通常論文]
     
    本研究では,積雪寒冷地で観測される地盤の凍上・融解現象を簡略モデル化した応力変形・熱伝導・飽和-不飽和浸透連成FEM解析プログラムを開発するとともに,当該プログラムを用いて凍上試験の数値実験を行い,試験結果との比較検討により,導入した支配方程式の妥当性や解析パラメーターの設定方法など提案する数値解析手法の適用性について検証した.また,実務設計レベルでの利用を想定し,凍結融解作用を受けるアスファルト舗装の数値シミュレーションを行い,凍上時および融解時の舗装構造の力学挙動を把握するとともに,道路舗装の理論的設計方法を用いて,路床の凍上・融解現象がアスファルト舗装の構造設計に及ぼす影響を評価した.その結果,凍上・融解現象がアスファルト舗装の疲労破壊に強い影響を及ぼすことを明らかにした.
  • 石川 達也, 木次谷 一平, 所 哲也, 赤川 敏
    土木学会論文集E1(舗装工学) 70 3 I_65 - I_70 Japan Society of Civil Engineers 2015年 [査読無し][通常論文]
     
    土の凍上量の予測式として「高志の式」が多用されているが,同式は土被り圧100kPa以上の飽和地盤で有効と考えられており,表層地盤などの不飽和状態の低土被り圧領域では,予測値が実際よりも大きくなる傾向にある.本研究では,寒冷地舗装構造の路床を想定した低土被り圧下における不飽和土の凍上量の推定方法として,有効応力を土被り圧とサクションの和で表した修正高志の式と吸水量,有効土被り圧,初期飽和度等を考慮可能な簡易凍上モデルを提案した.また,表層地盤を模擬した低い上載圧の凍上試験と保水性試験を行い,従来式と提案式を用いて試験結果をフィッティングしそれぞれの適用性を検証した.その結果,低土被り圧領域では,修正高志の式や簡易凍上モデルの予測精度が従来式よりも向上することを明らかにした.
  • Tatsuya Ishikawa, Seiichi Miura, Etsuo Sekine
    Transportation Geotechnics 1 4 157 - 170 2014年12月01日 [査読無し][通常論文]
     
    This study examines a simplified and practical prediction method for the cumulative residual settlement of ballasted track under repeated train passages, and the applicability and usefulness of the proposed method are discussed by comparing the experimental results of cyclic loading tests of model ballasted track structures with the analytical results. As the results, this study proposed a new analytical procedure with iterative calculation by linear elastic Finite Element (FE) analysis, which can evaluate the effects of continuous rotation of principal stress axis due to moving-wheel loads by taking into consideration the cumulative strain characteristics of ballast obtained from laboratory element tests such as multi-ring shear tests adopting the moving-wheel loading method in terms of the practical use. In addition, it was revealed that when laboratory element tests with high accuracy was conducted under experimental conditions similar to the actual phenomena in order to grasp the cumulative strain characteristics of ballast and then plastic deformation analysis was performed based on the findings above, the proposed analytical procedure could roughly estimate the cyclic plastic deformation of railroad ballast under repeated moving-wheel loads even with a simple linear elastic FE analysis. These findings confirm sufficient applicability of the proposed analytical procedure to the estimation of the cumulative residual settlement observed at ballasted track structures subjected to repeated train passages.
  • T. Ishikawa, S. Miura, E. Sekine
    Geotechnical Engineering 45 56 - 66 2014年03月01日 [査読無し][通常論文]
     
    This study presents an experimental, analytical and numerical studies to elucidate the dynamic response of ballasted track structures subjected to horizontal seismic motions. First, a series of shaking table tests for one-third small-scale model ballasted tracks was performed. As the results, it was revealed that the existence of grouted layer had a serious influence on the seismic performance of ballasted track structures. Next, numerical simulations of the shaking table tests were conducted with a newly proposed analytical procedure which utilizes FE analysis considering the cumulative strain characteristics of ballast. As the results, it was revealed that as the analytical procedure could roughly estimate the residual displacement of railroad ballast after seismic motions, it was effective to evaluate the seismic performance of ballasted track structures for practical use. Copyright © 2014 Southeast Asian Geotechnical Society (SEAGS). All Rights Reserved.
  • A. Inam, T. Ishikawa, S. Miura
    Geotechnical Engineering 45 74 - 84 2014年03月01日 [査読無し][通常論文]
     
    Nowadays, in order to economize the cost of pavements, recycled crusher-run (recycled concrete) that is recycled material is employed as base course material instead of natural crusher-run (andesite). Therefore, mechanical response of recycled crusher-run is required to evaluate in order to construct quality roads with minimum cost. In this research paper, an attempt is made to determine strengthdeformation characteristics of unsaturated recycled crusher-run material, under various loading conditions and saturation degrees. In addition, cyclic plastic deformation behaviour of two types of materials that are natural crusher-run (andesite) and recycled crusher-run (recycled concrete) is compared and analysed. A series of laboratory element test were carried out by using multi-ring shear apparatus, which can take in to account the rotation of principal stress axis. The experimental results show that, cyclic plastic deformation considerably enhances due to the rotation of principal stress axis under repeated axial and shear loading tests. Moreover, cyclic plastic deformation of recycled crusher-run material increases to some extent when compared with natural crusher-run material under same experimental conditions. Copyright © 2014 Southeast Asian Geotechnical Society (SEAGS). All Rights Reserved.
  • Tatsuya Ishikawa, Yuan Zhang, Tetsuya Tokoro, Seiichi Miura
    SOILS AND FOUNDATIONS 54 1 67 - 80 2014年02月 [査読有り][通常論文]
     
    This paper proposes a testing method for evaluating the effect of water content on the deformation strength characteristics of unsaturated subbase course materials. A medium-size triaxial apparatus for unsaturated soils is newly developed in order to examine the mechanical behavior of unsaturated subbase course materials subjected to fluctuations in water content and to shorten the testing time It adopts the pressure membrane method with hydrophilic microporous membrane filters, instead of the pressure plate method with ceramic disks, and controls both pore air pressure and pore water pressure at the cap and the pedestal separately. The results of the proposed testing method, carried out by this apparatus, are shown to conform well to the results of previous researches. This indicates that the medium-size triaxial apparatus for unsaturated soils is highly useful for triaxial compression tests and water retentivity tests on unsaturated granular base course materials and for shortening the total testing time (C) 2014 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved
  • 川端 伸一郎, 石川 達也, 亀山 修一
    地盤工学ジャーナル 9 1 1 - 13 The Japanese Geotechnical Society 2014年 [査読無し][通常論文]
     
    本研究では,新たに作製した凍結融解CBR試験装置を用いて,凍結融解作用が粒状路盤材(C-40)の支持力特性に与える影響を調べた。C-40のCBRは,すべての含水比条件で凍結融解履歴によって減少することが明らかとなった。凍結作用は粒子内の水分を排出させる効果があり,この現象によって1) 粒子間の摩擦が減少する,2) 間隙構造が変化する,と考えられ,これらの要因でCBRが低下することを示した。また,1) 粒子間摩擦の減少によるCBRの低下は,時間経過によってその値が回復するのに対して,2) 間隙構造の変化による場合は,時間による回復はみられないことを明らかにした。
  • Yuan Zhang, Tatsuya Ishikawa, Tetsuya Tokoro, Tomoyoshi Nishimura
    Transportation Geotechnics 1 2 74 - 89 2014年 [査読無し][通常論文]
     
    The aim of this study is to clarify strength characteristics of a subbase course material changed due to the degree of saturation and the strain rate. A series of monotonic triaxial compression tests was carried out under desired unsaturated and strain rate conditions using a medium-size triaxial compression apparatus. The test results indicate that the degree of saturation can significantly affect shear behaviors of the subbase course material in terms of the shear strength and deformability. On the other hand, the triaxial compression tests with the strain rate of 0.5%/min were conducted as well as those with 0.05%/min, which has been usually employed. The experimental results show that the mechanical behavior of the subbase course material is susceptible to the strain rate, and such relations can vary depending on the degree of saturation in shear. Furthermore, change in the strength parameters such as the total internal friction angle and the total cohesion resulting from the degree of saturation and the strain rate effects will be discussed. The calculation results show that the effects of degree of saturation and strain rate on the total internal friction angle appear to be negligible, while the total cohesion can be affected by the degree of saturation and the strain rate. More specifically, the failure envelope for the subbase course material is nonlinear under the low suction ranges. Therefore, the failure surface drawn through the failure envelope with respect to the matric suction is curved surface. The failure surface for unsaturated specimens with higher strain rate is located above that with lower strain rate. © 2014 Elsevier Ltd.
  • 石川 達也, 張 媛, 川端 伸一郎, 亀山 修一, 所 哲也
    土木学会論文集E1(舗装工学) 69 3 I_207 - I_214 Japan Society of Civil Engineers 2013年 [査読無し][通常論文]
     
    本研究は,積雪寒冷地の道路舗装における粒状路盤の力学的応答の長期性能評価手法を構築するため,中型不飽和三軸試験機を用いた不飽和粒状路盤材のレジリエントモデュラス試験方法を提案するとともに,凍結融解CBR試験や試験舗装におけるFWD試験とレジリエントモデュラス試験との試験結果の関連性について議論した.その結果,本研究で開発した試験機および提案する試験方法が,不飽和粒状路盤材のレジリエントモデュラス試験として有用であることを示すとともに,凍結融解作用とそれに伴う含水状態の季節変動が,粒状路盤材の復元変形特性を低下させ,舗装構造の疲労寿命に強い影響を及ぼすことを明らかにした.
  • 川端 伸一郎, 石川 達也, 豊田 邦男, 山内 智, 亀山 修一
    土木学会論文集E1(舗装工学) 69 3 I_191 - I_198 Japan Society of Civil Engineers 2013年 [査読無し][通常論文]
     
    NEXCO基準の凍上試験(NEXCO法)に対して,結果のばらつきを抑制するために凍結方法の改良を行った.また,JGS基準の凍上試験(JGS法)を路床土や路盤材にも適応できるようにφ150mmまで大口径化した試験装置を作製し,試験方法や供試体寸法の違いが凍上試験結果に及ぼす影響を調べた.NEXCO法は,凍結方法を空冷式から冷媒循環式に変更したことで安定した結果を得ることが可能となった.φ150mmのJGS法と一般に普及しているφ100mmのJGS法の結果に違いはみられず,大口径化した影響は少ないことが示された.NEXCO法とJGS法が非凍上性と判定する値は,ほぼ一致することが明らかとなった.しかし,両法が一致した結果を得られる範囲は,JGS法の凍上速度が0.2mm/h程度までであった.
  • 川端 伸一郎, 石川 達也, 村山 巧, 亀山 修一
    土木学会論文集E1(舗装工学) 68 3 I_115 - I_122 2012年12月 [査読有り][通常論文]
  • 石川 達也, 張 媛, 所 哲也
    土木学会論文集E1(舗装工学) 68 3 I_105 - I_113 2012年12月 [査読有り][通常論文]
  • Influence of moisture content, loading speed and degree of compaction on the shear behavior of sandy soil
    Zhang, Y, Ishikawa, T, Tokoro, T, Shibuya S
    Proceedings of the 2nd International Symposium on Constitutive Modeling of Geomaterials - Advances and New Applications - 501 - 506 2012年10月 [査読無し][通常論文]
  • Influence of freeze-thaw action on hydro-mechanical behavior of unsaturated crushable volcanic soils
    Ishikawa, T, Tokoro, T
    Proceedings of the international workshop on Advances in Multiphysical Testing of Soils and Shales 143 - 148 2012年09月 [査読無し][通常論文]
  • Aasim Inam, Tatsuya Ishikawa, Seiichi Miura
    SOILS AND FOUNDATIONS 52 3 465 - 480 2012年06月 [査読有り][通常論文]
     
    It is generally observed that the stress state induced through traffic loads inside the substructure of pavements cannot be exactly reproduced in laboratory element tests. Moreover, there are not sufficient studies that examine the behavior of granular material under unsaturated conditions, although such conditions are very prevalent in pavement structures. In this research, an attempt is made to determine the cyclic plastic deformation characteristics of unsaturated granular base course material, and to examine the effect of the rotation of the principal stress axis (experienced by pavement elements under traffic loads) on the mechanical behavior of unsaturated granular base course material by applying various loading methods. A series of laboratory element tests using a multi-ring shear apparatus, which can take into account the rotation of the principal stress axis, were carried out on granular base course material under different moisture contents. The experimental results show that the moisture content has an obvious effect on both the shear behavior and the cyclic plastic deformation of granular base course material. However, the moisture content for the maximum deformation of granular base course material varies according to the loading method. It is also explained that cyclic plastic deformation considerably increases due to the rotation of the principal stress axis under repeated axial and shear loading tests. Therefore, the principal stress axis rotation has a significant influence on the cyclic plastic deformation of unsaturated granular base course material. (C) 2012 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.
  • T. Ishikawa, S. Kawabata, S. Kameyama, R. Abe, T. Ono
    ADVANCES IN TRANSPORTATION GEOTECHNICS II 118 - 124 2012年 [査読無し][通常論文]
     
    This paper examines the effects of freezing and thawing on the mechanical behavior of granular base under unsaturated conditions through the long-term field measurement and FWD tests for pavement structure subjected to freeze-thaw actions, and by performing CBR tests for freeze-thawed base course material using a newly developed test apparatus. We also evaluate the influences of the change in the bearing capacity of granular base due to freeze-thawing on the fatigue life of pavement structures by applying the theoretical design method for pavement structures in consideration of the effects found in the above-mentioned experiments. As the results, it was revealed that the bearing capacity of granular base increases in freezing season and decreases due to increment of the water content in thawing season. This indicates that the freeze-thaw of granular base has a strong influence on the fatigue life of pavement structure in cold regions.
  • T. Ishikawa, Y. Zhang, H. Segawa, S. Miura, T. Tokoro
    ADVANCES IN TRANSPORTATION GEOTECHNICS II 534 - 540 2012年 [査読無し][通常論文]
     
    This paper proposes a testing method for evaluating the effect of water content on the deformation-strength characteristics of unsaturated base course materials. A medium-size triaxial apparatus for unsaturated soils was newly developed in order to examine the mechanical behavior of unsaturated base course materials subjected to fluctuation in water content and to shorten the testing time. It adopts the pressure membrane method with hydrophilic microporous membrane filters instead of the pressure plate method with ceramic disks, and controls both pore air pressure and pore water pressure at cap and pedestal separately. Results show that the proposed testing method carried out on this apparatus conform well to the results of previous researches. This indicates that the medium-size triaxial apparatus is highly useful at triaxial compression tests and water retention tests of unsaturated granular base course materials and in shorten the total testing time.
  • A. Inam, T. Ishikawa, S. Miura
    ADVANCES IN TRANSPORTATION GEOTECHNICS II 213 - 218 2012年 [査読無し][通常論文]
     
    This research paper proposes a testing method to determine cyclic plastic deformation characteristics of unsaturated recycled crusher-run material, and accordingly examines the effect of moisture content under single-point loading and moving-wheel loading. In Japan, natural crusher-run material is employed in pavements for base course layer. Nowadays, in order to economize the cost of pavements, recycled crusher-run material made from construction waste is also used as base course material for low volume roads. A series of laboratory element test using multi-ring shear apparatus were carried out on recycled crusher-run material under different degrees of saturation. The experimental results show that, moisture content has obvious effect on cyclic plastic deformation of recycled crusher-run material. It is also explained that cyclic plastic deformation significantly increases under moving-wheel loading tests. Moreover, cyclic plastic deformation of recycled crusher-run material increases to some extent when compared with natural crusher-run material under same experimental conditions.
  • 石川達也, 川端伸一郎, 亀山修一, 安倍隆二, 小野丘
    土木学会論文集 E1(舗装工学)(Web) 67 3 I_109 - I_116 2011年12月 [査読有り][通常論文]
  • Effect of moisture content on cyclic deformation characteristics of granular material under moving wheel loads
    Inam, A, Ishikawa, T, Miura, S
    Proceedings of the 5th Asia-Pacific Conference on Unsaturated Soils 611 - 616 2011年11月 [査読無し][通常論文]
  • Tatsuya Ishikawa, Seiich Miura
    SOILS AND FOUNDATIONS 51 5 785 - 799 2011年10月 [査読有り][通常論文]
     
    The objective of this study is to evaluate the effect of freeze-thaw action on the deformation-strength characteristics of crushable volcanic coarse-grained soils, wherein significant particle breakage occurs even under relatively low stress levels and saturated conditions. A series of monotonic triaxial compression tests was performed for volcanic coarse-grained soils under various freeze-thaw histories. On the basis of the test results, we examined the above-mentioned effect and the relationship between the degree of particle breakage and the freeze-thaw history. The results indicate that the degree of particle breakage under consolidation and shear increased with freeze-thaw action; and consequently, the strength and the stiffness of the soils decreased with an increase in the number of freeze-thaw cycles. Moreover, to examine the influence of freeze-thaw action on the single-particle hardness of volcanic coarse-grained soils, single-particle crushing tests were conducted. The test results revealed that volcanic soil particles become more fragile after being exposed to freeze-thaw action, and as a result, the degree of particle breakage increases. These results indicate that the freeze-thaw action has a strong influence on the deformation-strength characteristics of crushable volcanic soils in terms of an increase in particle breakage, even if the soils lack frost-heave characteristics.
  • Dependency of shear behavior of recycled crusher-run material on moisture content evaluation by multi-ring shear testing
    Inam, A, Ishikawa, T, Miura, S
    Proceedings of the 2nd Japan-Korea Joint Workshop on Unsaturated Soils and Ground 189 - 198 2011年09月 [査読無し][通常論文]
  • 石川 達也, 梶原 逸朗, 松田 理, 成田 吉弘
    工学教育研究講演会講演論文集 23 59 536 - 537 公益社団法人日本工学教育協会 2011年08月 [査読無し][通常論文]
  • Tatsuya Ishikawa, Etsuo Sekine, Seiichi Miura
    Canadian Geotechnical Journal 48 5 691 - 703 2011年05月 [査読有り][通常論文]
     
    This paper describes a new testing method to examine the mechanical behavior of railroad ballast subjected to repeated train passages on ballasted track. Two types of cyclic loading tests, namely a single-point loading test and a movingwheel loading test, were performed with small-scale models of ballasted track. Next, a "multi-ring shear apparatus" was developed as a type of torsional simple shear apparatus, and the applicability of a newly proposed multi-ring shear test to an element test of railroad ballast subjected to moving-wheel loads was examined by comparing the results of multi-ring shear tests with those of small-scale model tests. As a result, it was recognized that cumulative strain obtained from multi-ring shear tests is almost equivalent to the one derived from small-scale model tests. Moreover, it was revealed that the difference between loading methods has a considerable influence on the cyclic plastic deformation of railroad ballast because settlement in a moving-wheel loading test was much larger than the one in a single-point loading test. These results lead to the conclusion that a multi-ring shear test has an excellent applicability to the estimation of deformation behavior of granular materials subjected to moving-wheel loads.
  • Tatsuya Ishikawa, Etsuo Sekine, Seiichi Miura
    CANADIAN GEOTECHNICAL JOURNAL 48 5 691 - 703 2011年05月 [査読有り][通常論文]
     
    This paper describes a new testing method to examine the mechanical behavior of railroad ballast subjected to repeated train passages on ballasted track. Two types of cyclic loading tests, namely a single-point loading test and a moving-wheel loading test, were performed with small-scale models of ballasted track. Next, a "multi-ring shear apparatus" was developed as a type of torsional simple shear apparatus, and the applicability of a newly proposed multi-ring shear test to an element test of railroad ballast subjected to moving-wheel loads was examined by comparing the results of multi-ring shear tests with those of small-scale model tests. As a result, it was recognized that cumulative strain obtained from multi-ring shear tests is almost equivalent to the one derived from small-scale model tests. Moreover, it was revealed that the difference between loading methods has a considerable influence on the cyclic plastic deformation of railroad ballast because settlement in a moving-wheel loading test was much larger than the one in a single-point loading test. These results lead to the conclusion that a multi-ring shear test has an excellent applicability to the estimation of deformation behavior of granular materials subjected to moving-wheel loads.
  • 粒状路盤の力学挙動に及ぼす凍結融解作用の影響評価
    石川 達也, 安倍 隆二, 吉田 有喜, 三浦 清一
    土木学会舗装工学論文集 15 201 - 209 2010年12月 [査読有り][通常論文]
  • 所哲也, 石川達也, 赤川敏
    地盤工学ジャーナル(Web) 5 4 603 - 613 2010年12月 [査読無し][通常論文]
  • Application of 3D-DEM with Seepage Analysis to Numerical Simulation of rainfall-Induced Slope Failure
    Capriles, C.A, Ishikawa, T, Miura, S
    Proceedings of International Symposium on Geomechanics and Geotechnics From Micro to Macro (IS-Shanghai2010) 689 - 693 2010年10月 [査読無し][通常論文]
  • Effect of freeze-thaw action on strength characteristics of unsaturated coarse-grained soil
    Ishikawa, T, Ito, K, Miura, S
    Proceedings of 5th International Conference on Unsaturated Soils (UNSAT10) 549 - 554 2010年09月 [査読無し][通常論文]
  • 川村志麻, 三浦清一, 石川達也, 横浜勝司
    土木学会論文集 C(Web) 66 3 577 - 594 2010年08月 [査読有り][通常論文]
  • 石川達也, 関根悦夫
    応用力学論文集(CD-ROM) 13 1031 - 1039 2010年08月 [査読有り][通常論文]
  • Tatsuya Ishikawa, Tetsuya Tokoro, Kohei Ito, Seiichi Miura
    SOILS AND FOUNDATIONS 50 3 431 - 440 2010年06月 [査読有り][通常論文]
     
    This paper proposes new testing methods for evaluating the effects of freeze-thaw action on the deformation-strength characteristics and the water retention-permeability characteristics of granular materials under unsaturated conditions. A triaxial apparatus and a permeability apparatus for unsaturated soils, with cooling systems to control the temperature of soil specimens and use the pressure membrane method instead of the pressure plate method, were newly developed in order to examine the hydro-mechanical behavior of unsaturated soils subjected to the freeze-thaw sequence, as experienced by in-situ soils in cold regions. Results indicate that the proposed testing methods with these newly developed test apparatuses are highly useful in the evaluation of the effect of freeze-thaw action on the hydro-mechanical behavior of unsaturated granular materials and in the reduction of total testing time.
  • S. Kawamura, S. Miura, T. Ishikawa
    Geotechnical Special Publication 202 152 - 158 2010年 [査読無し][通常論文]
     
    Collapse of volcanic slopes induced by rainfall has been frequently induced in Hokkaido, Japan, especially the middle southern area. It has been known that volcanic slopes in Hokkaido have a strong potential to cause such failure. The objective of this study is to reveal failure mechanism of volcanic slopes caused by both rainfall and freeze-thaw actions. A series of model tests was performed on volcanic slopes having several moisture contents. In particular, the effect of freeze-thaw actions on mechanical behavior at failure was investigated detailedly. © 2010 ASCE.
  • 移動輪荷重作用下の粒状路盤の力学挙動に及ぼす含水状態の影響評価
    石川 達也, 細田 充, 三浦 清一, 関根 悦夫
    土木学会舗装工学論文集 14 9 - 17 2009年12月 [査読有り][通常論文]
  • Development of triaxial apparatus for permeability test of unsaturated soil using pressure membrane method
    Tokoro, T, Ishikawa, T, Miura, S
    Proceedings of the 4th Asia-Pacific Conference on Unsaturated Soils 179 - 184 2009年11月 [査読無し][通常論文]
  • Influence of freeze-thaw action on soil water characteristics of crushable volcanic coarse-grained soil
    Ishikawa, T, Ito, K, Miura, S
    Proceedings of the 4th Asia-Pacific Conference on Unsaturated Soils 159 - 164 2009年11月 [査読無し][通常論文]
  • Plastic deformation analysis of granular base under cyclic moving loads by cumulative damage model
    Ishikawa, T, Sekine, E, Miura, S
    Proceedings of the 5th JAPAN/CHINA Workshop on Pavement Technologies 113 - 119 2009年09月 [査読無し][通常論文]
  • Effect evaluation of roadbed stiffness on bearing capacity of railroad ballast with discontinuous analysis
    Ishikawa, T, Kamei, T, Sekine, E, Ohnishi, Y
    Proceedings of the 8th International Conference on the Bearing Capacity of Roads, Railways and Airfields 2 1207 - 1218 2009年06月 [査読無し][通常論文]
  • Failure mechanism of volcanic slope due to rainfall and freeze-thaw action
    Kawamura, S, Miura, S, Ishikawa, T, Ino, H
    Proceedings of IS Kyoto09 25 - 31 2009年05月 [査読無し][通常論文]
  • Application of coupled thermo-mechanical analysis to slope behavior during freezing and thawing in cold regions
    Ishikawa, T, Sato, M, Miura, S. Akagawa, S, Kawamura, S
    Proceedings of IS Kyoto09 409 - 415 2009年05月 [査読無し][通常論文]
  • Tatsuya Ishikawa, Etsuo Sekine, Seiichi Miura
    CJWPT 2009: PROCEEDINGS OF THE 5TH CHINA-JAPAN WORKSHOP ON PAVEMENT TECHNOLOGIES 113 - + 2009年 [査読有り][通常論文]
     
    This paper presents a simple method to estimate the cyclic plastic deformation of ballasted track subjected to repeated train passages in terms of the strength and deformation characteristics of coarse granular materials. A new analytical procedure with linear elastic FE analysis considering the cumulative strain characteristics of poorly-graded crushed stone, that is ballast, which were derived from two types of multi-ring shear tests, namely a fixed-place loading test and a moving wheel loading test, was proposed. As the results, it was revealed that the newly proposed analytical procedure could roughly estimate the residual settlement of railroad ballast under cyclic moving wheel loads, by comparing test results of cyclic loading tests for small scale model of ballasted track with the results of FE analysis.
  • T. Ishikawa, S. Miura, T. Tokoro
    Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering 1 833 - 836 2009年 [査読無し][通常論文]
     
    This paper proposes new testing methods for evaluating the effects of freeze-thaw action on the deformation-strength characteristics and water retention-permeability characteristics of granular materials in unsaturated conditions. A triaxial and a permeability apparatus, which have a cooling system to control the temperature of the soil specimen, were developed in order to examine the hydro-mechanical behavior of unsaturated soils subjected to freeze-thaw sequence similar to that experienced by in-site soil in cold regions. Results indicate that the proposed testing methods with the newly developed test apparatuses are highly useful in the evaluation of the effects of the freeze-thaw action on the hydro-mechanical behavior of unsaturated soils. © 2009 IOS Press.
  • 不連続体解析による路床剛性の異なる粒状路盤の支持力挙動評価
    石川 達也, 亀井 威彦, 関根 悦夫, 大西 有三
    土木学会舗装工学論文集 13 125 - 132 2008年12月 [査読有り][通常論文]
  • Application of DDA to mechanical behavior of granular base-subgrade system
    Ishikawa, T, Sekine, E, Ohnishi, Y
    Proceedings of International Mini-Symposium for Numereical Discontinuous Analysis 41 - 52 2008年11月 [査読無し][通常論文]
  • Numerical modeling for mechanical behavior of granular materials subjected to freeze-thaw action with DEM
    Ishikawa, T, Miura, S
    Proceedings of the 12th International Conference on Computer Methods and Advances in Geomechanics 1 1219 - 1226 2008年10月 [査読無し][通常論文]
  • 石川達也, 尾崎悠太, 三浦清一
    土木学会論文集 C(Web) 64 3 712-717 (J-STAGE)  2008年09月 [査読有り][通常論文]
  • Influence of freeze-thaw action on mechanical behavior of saturated crushable volcanic soil
    Ishikawa, T, Miura, S, Ito, K, Ozaki, Y
    Proceedings of 4th International Symposium on deformation characteristics of geomaterials (IS-Atalanta2008) 2 557 - 564 2008年09月 [査読無し][通常論文]
  • T. Ishikawa, M. Hosoda, S. Miura, E. Sekine
    ADVANCES IN TRANSPORTATION GEOTECHNICS 185 - 191 2008年 [査読無し][通常論文]
     
    This paper presents an experimental study to evaluate the effects of water content on the mechanical behavior of gravel subjected to moving wheel loads. First, two types of small scale model tests which adopted a fixed-place loading method and a moving loading method were performed with a base course material under air-dried condition and saturated condition. Next, two types of multi-ring shear tests which could consider a change in direction of principal stresses like traffic loads were performed likewise. Based on test results, the relationships between the water content of test samples and the deformation-strength characteristics were examined. As the results, it was revealed that the shear strength of gravel decreased and the cumulative residual strain increased due to the saturation in both tests, regardless of loading methods. This indicates that the water content of gravel influences the mechanical behavior of granular roadbed strongly.
  • 移動輪荷重を受ける粒状材料の累積損傷度理論による塑性変形解析
    関根 悦夫, 石川 達也, 三浦 清一
    土木学会舗装工学論文集 12 47 - 55 2007年12月 [査読有り][通常論文]
  • Effect evaluation of moving load on cyclic deformation of crushed stone
    Ishikawa, T, Sekine, E
    Proceedings of the 13th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering 1 435 - 438 2007年12月 [査読無し][通常論文]
  • Fundamental study for slope failure of volcanic soil ground by DDA
    Ishikawa, T, Kawamura, S, Miura, S, Ohnishi, Y
    Proceedings of 8th International Conference on the Analysis of Discontinuous Deformation 61 - 66 2007年08月 [査読無し][通常論文]
  • Effect of moving wheel load on cyclic deformation of granular material
    Ishikawa, T, Sekine, E, Miura, S
    Proceedings of the 4th JAPAN/CHINA Workshop on Pavement Technologies 41 - 50 2007年07月 [査読無し][通常論文]
  • Influence of degree of saturation on strength characteristics of crushable volcanic coarse-grained soils
    Ishikawa, T, Ozaki, Y, Miura, S
    Proceedings of the 3rd Asian Conference on Unsaturated Soils 223 - 229 2007年04月 [査読無し][通常論文]
  • 石川達也, 関根悦夫, 泉剛生
    土木学会論文集 F 63 4 517 - 529 2007年 [査読有り][通常論文]
  • 石川達也, 関根悦夫
    土木学会論文集 F 63 4 506 - 516 2007年 [査読有り][通常論文]
  • 石川 達也, 関根 悦夫, 三和 雅史, 大西 有三
    応用力学論文集 10 513 - 522 Japan Society of Civil Engineers 2007年 [査読無し][通常論文]
     
    This paper examines the effects of particle properties such as particle shape and grain size distribution of particle assemblage on the bearing capacity of railroad ballast in numerical simulations with discontinuous analysis. Here, two evaluation indexes of particle shape, namely "angularity" and "sphericity", were employed. To evaluate the effect quantitatively, a series of numerical simulations that regard a ballast particle as a regular or an irregular polygon were performed. As the result, it can be observed that the particle shape of numerical models, especially the angularity has a greater effect on the bearing capacity of railroad ballast than the grain size distribution, and that the imitation of the shape of real ballast particles makes numerical results similar to experimental results.
  • 粒状材料の繰返し変形挙動に及ぼす移動輪荷重の影響評価
    石川 達也, 関根 悦夫, 三浦 清一
    土木学会舗装工学論文集 11 23 - 31 2006年12月 [査読有り][通常論文]
  • 石川 達也, 玉置 和美, 三浦 清一
    土木学会応用力学論文集 9 641 - 648 土木学会 2006年09月 [査読有り][通常論文]
  • Strength characteristics of crushable volcanic soils at various degrees of saturation
    Ishikawa, T, Miura, S. Yokohama, S, Mijares, R.G
    Proceedings of IS Yamaguchi06 121 - 126 2006年09月 [査読無し][通常論文]
  • Effect Evaluation of particle shape on mechanical behavior of railroad ballast with discontinuous analysis
    Ishikawa, T, Kobayashi, K, Sekine, E, Ohnishi, Y
    Proceedings of IS Yamaguchi06 389 - 396 2006年09月 [査読無し][通常論文]
  • Influence of input parameters on energy loss in free fall tests with DDA
    Ishikawa, T, Miura, S, Ohnishi, Y
    Proceedings of 7th International Conference on the Analysis of Discontinuous Deformation 147 - 158 2005年12月 [査読無し][通常論文]
  • 繰返し荷重を受ける粒状材料の累積損傷度理論による塑性変形解析
    関根 悦夫, 石川 達也
    土木学会舗装工学論文集 10 53 - 60 2005年11月 [査読有り][通常論文]
  • Development and performance evaluation of multi-ring shear apparatus
    Ishikawa, T, Miura, S, Sekine, E
    Proceedings of Geotechnical Aspects and Processed Material in Design and Construction of Pavement and Rail Track 53 - 64 2005年09月 [査読無し][通常論文]
  • Evaluation of the effect of particle shape on the bearing capacity of railroad ballast with discontinuous analysis
    Ishikawa, T, Kobayashi, K, Sekine, E, Ohnishi, Y
    Proceedings of the 7th International Conference on the Bearing Capacity of Roads, Railways and Airfields 1/1(CD-ROM)52  2005年06月 [査読無し][通常論文]
  • Numerical Simulation of Shear Tests for Granular Materials with 3D DEM
    Ishikawa, T, Tamaki, K, Miura, S
    Proceedings of the 11th International Conference on Computer Methods and Advances in Geomechanics 2 65 - 72 2005年06月 [査読無し][通常論文]
  • T Ishikawa, K Tamaki, Y Ohnishi, S Miki
    Contribution of Rock Mechanics to the New Century, Vols 1 and 2 1227 - 1232 2004年 [査読無し][通常論文]
     
    This paper shows an analytical study to evaluate the effects of pore pressure on the strength and deformation characteristics of saturated granular materials. Six simulations of triaxial compression tests were performed regarding a constituent particle as an element of discontinuous analysis (DDA). The method to build pore pressure such as pore water pressure and frost heaving pressure into DDA and the applicability of the improved DDA to the shearing behavior of saturated granular materials at undrained condition were discussed. As the results, the numerical algorithm for detecting voids and outer circumference of granular assemblage and loading pore and lateral pressure was proposed, it was showed that the improved DDA can examine the action of pore pressure though there is room for further investigation.
  • T Ishikawa, E Sekine, A Khono, S Miura
    CYCLIC BEHAVIOUR OF SOILS AND LIQUEFACTION PHENOMENA 633 - 640 2004年 [査読無し][通常論文]
     
    This paper presents a method to estimate cyclic plastic deformation of railroad ballast, which is an assemblage of poorly-graded crushed stone, subjected to repeated train passages. First, to understand the behavior of railroad ballast under train loads, small scale model tests which adopt moving loads as the loading method were performed. Second, to examine their strength and deformation characteristics, cyclic loading and monotonic loading triaxial compression tests were performed. Finally, to develop a simple prediction method of residual settlement in ballasted track under repeated loads, the application method of Finite Element Method was discussed by simulating small scale model tests of ballasted track with linear elastic FE analysis. This paper proposes an estimation method to predict residual settlement of railroad ballast under repeated moving loads in terms of the strength and deformation characteristics of coarse granular materials.
  • Modeling for Energy Dissipation in Free Fall Tests of Spherical Stone with Discontinuous Analysis
    Ishikawa, T, Ohnishi, Y, Jian Hong Wu, Nishiyama, S
    Proceedings of SRA03 1105 - 1110 2003年06月 [査読無し][通常論文]
  • T Ishikawa, E Sekine
    DEFORMATION CHARACTERISTICS OF GEOMATERIALS 841 - 848 2003年 [査読無し][通常論文]
     
    This study presents an experimental study to elucidate the dynamic response of railroad ballast subjected to seismic loads. A series of shaking table tests for the uniformly graded crushed stone was performed. In these tests, a full scale model of railroad ballast as well as a one-third scale model with uniformly graded crushed stone whose mean grain size was different from ballast despite similar grain size distribution was used. Based on test results, the seismic stability and ductility beyond failure of railroad ballast are quantitatively evaluated associated with the observed movement of ballast particles inside railroad ballast. Moreover, effects of the scale factor between prototypes and the models on the dynamic response of granular materials are discussed associated with the strength and deformation characteristics of ballast and gravel obtained by triaxial compression tests. This study proposes an evaluation method of seismic stability and ductility correspondent to magnitude of earthquake motions.
  • Shaking table tests of coarse granular materials with discontinuous analysis
    Ishikawa, T, Ohnishi, Y, Sekine, E
    Proceedings of 5th International Conference on the Analysis of Discontinuous Deformation 181 - 188 2002年10月 [査読無し][通常論文]
  • 「MTT作業計画支援システム」の試行について
    奥村 陽一, 沼倉 明夫, 小野 重亮, 蔭山 朝昭, 石川 達也, 三和 雅史, 藤森 寿雄, 森 忠夫, 都築 達彦
    土木学会鉄道力学論文集 6 55 - 59 2002年07月 [査読有り][通常論文]
  • 横圧載荷による木まくらぎ状態判定試験
    小林 潤, 石川 達也, 小野 重亮, 峰岸 大介
    土木学会鉄道力学論文集 6 49 - 54 2002年07月 [査読有り][通常論文]
  • Effects of Moving Wheel Load on Cyclic Deformation of Railroad Ballast
    Ishikawa, T, Sekine, E
    Proceedings of Railway Engineering-2002 2002年07月 [査読無し][通常論文]
  • Modeling the Optimal MTT Operation Schedule and Its Application to Japanese Railway Network System,
    Miwa, M, Ishikawa, T, Okumura, Y, Oyama, T
    Proceedings of Railway Engineering-2002 2002年07月 [査読無し][通常論文]
  • Modeling the Optimal Decision-Making for Multiple Tie Tamper Operations
    Miwa, M, Ishikawa, T, Oyama, T
    Proceedings of WCRR'01 2001年11月 [査読無し][通常論文]
  • 三和雅史, 石川達也, 大山達雄
    土木学会論文集 681 51 - 65 2001年07月 [査読有り][通常論文]
  • A Study on the Time Dependency of Granular Materials with DDA
    Ishikawa, T, Ohnishi, Y
    Proceedings of 4th International Conference on the Analysis of Discontinuous Deformation 271 - 280 2001年06月 [査読無し][通常論文]
  • Application of discontinuum analysis to cyclic plastic deformation of coarse granular materials
    Ishikawa, T, Ohnishi, Y
    Proceedings of the 10th International Conference on Computer Methods and Advances in Geomechanics 321 - 324 2001年01月 [査読無し][通常論文]
  • Application of discontinuum analysis to track deterioration in ballasted track
    Ishikawa, T, Ohnishi, Y, Namura, A
    Proceedings of Railway Engineering-2000 2000年07月 [査読無し][通常論文]
  • Modeling the transition process of railway track irregularity and its application to the optimal decision-making for multiple tie tamper operations
    Miwa, M, Ishikawa, T, Oyama, T
    Proceedings of Railway Engineering-2000 2000年07月 [査読無し][通常論文]
  • 石川達也, 大西有三, 堀池高広
    土木学会論文集 645 15 - 28 2000年03月 [査読有り][通常論文]
  • Modeling the transition process of railway track irregularity and its application to decision making for maintenance strategy
    Miwa, M, Ishikawa, T, Oyama, T
    Proceedings of WCRR'99 1999年10月 [査読無し][通常論文]
  • 鉄道構造物等設計標準[有道床軌道]に準じた構造解析手法に関する一考察
    石川 達也, 内田 雅夫
    土木学会鉄道力学論文集 3 31 - 36 1999年06月 [査読有り][通常論文]
  • T Ishikawa, M Kamon, A Namura
    PRE-FAILURE DEFORMATION CHARACTERISTICS OF GEOMATERIALS, VOL 1 783 - 791 1999年 [査読無し][通常論文]
     
    This paper presents experimental and analytical studies to elucidate such phenomenon observed in ballasted railway track that irregularity of rail level under train passage gets worse, that is "track deterioration", in terms of cyclic deformation of railroad ballast. Vertical cyclic loading tests were performed with full-scale track attaching special test facilities, and the application method of the discrete analysis to the cyclic deformation of railroad ballast was also discussed by simulating full-scale track tests with DDA and FEM. As the result, it was concluded that the cyclic deformation of railroad ballast occurred by the movement of ballast particles, accompanied by the fabric transformation of particle alignment.
  • T Ishikawa, Y Ohnishi
    ICADD-3: THIRD INTERNATIONAL CONFERENCE ON ANALYSIS OF DISCONTINUOUS DEFORMATION - FROM THEORY TO PRACTICE, PROCEEDINGS 107 - 116 1999年 [査読無し][通常論文]
     
    This paper presents an analytical study to elucidate the cyclic plastic deformation of railroad ballast in ballasted railway track under train passage, that is "track deterioration". The simulations of full-scale vertical cyclic loading tests of railroad track regarding a ballast particle as a DDA block were performed, and the applicability of DDA to the cyclic plastic deformation of railroad ballast was discussed. It was found that the cyclic plastic deformation of railroad ballast could be defined as the fabric transformation of particle alignment accompanied by sliding between particles. DDA is useful to trace the movement of particles and to unveil the complex deformation mechanics of granular ballast materials.
  • 石川達也, 大西有三
    土木学会論文集 589 205 - 217 1998年03月 [査読有り][通常論文]
  • 石川達也, 須長誠, DONG J, 名村明
    土木学会論文集 575 169 - 177 1997年09月 [査読有り][通常論文]
  • DDA applied to deformation analysis of coarse granular materials (ballast)
    Ishikawa, T, Ohnishi, Y, Namura, A
    Proceedings of 2nd International Conference on the Analysis of Discontinuous Deformation 253 - 262 1997年07月 [査読無し][通常論文]
  • M Uchida, H Takai, T Ishikawa, E Yazawa, M Miwa
    INTERNATIONAL RAILWAY CONFERENCE ON BETTER JOURNEY TIME - BETTER BUSINESS 1996 8 189 - 198 1996年 [査読無し][通常論文]
  • 石川達也, 名村明
    土木学会論文集 512 47 - 59 1995年04月 [査読有り][通常論文]
  • T NAKAMURA, T ISHIKAWA, Y ASADA
    INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING 51 2 211 - 227 1992年 [査読有り][通常論文]
     
    Stress-strain response and fatigue failure of type 304 stainless steel at 650-degrees-C in air were investigated under proportional biaxial strain-controlled, tension-torsion loading. The loading program includes a wide variety of strain-time regimes of symmetric continuous, asymmetric continuous and hold-time cycles, with the strain rate ranging from 10(-5) to 10(-3) s-1 and the hold-time exceeding 600 s. The overstress concept is applied to evaluate the test results. A time/rate-dependent behavior of the internal stress and overstress is introduced through a long-term stress relaxation test under biaxial stress. The creep-fatigue damage model based on the overstress concept, which was previously suggested by the authors, is extended to a biaxial creep-fatigue life prediction.

書籍

  • Advances in Transportation Geotechnics II
    CRC Press 2012年08月
  • 舗装工学ライブラリー6 積雪寒冷地の舗装
    土木学会 2011年
  • 斜面の凍上被害と対策のガイドライン
    地盤工学会北海道支部 2010年03月
  • 地盤材料試験の方法と解説 第8編 特殊土の試験
    地盤工学会 2009年
  • 計算力学レクチャーシリーズ6不連続変形法(DDA)
    丸善 2005年

その他活動・業績

  • 高橋 浩晃, 勝俣 啓, 大園 真子, 橋本 武志, 青山 裕, 酒井 慎一, 松本 聡, 岡田 知己, 小菅 正裕, 寺川 寿子, 飯尾 能久, 中尾 茂, 上嶋 誠, 柴田 智郎, 大津 直, 高井 伸雄, 飯場 正紀, 渡部 要一, 菊地 優, 岡崎 太一郎, 白井 和貴, 西村 裕一, 石川 達也, 高瀬 裕也, 永井 宏, 宮森 保紀, 三宅 弘恵, 松島 信一, 浅野 公之, 重藤 迪子, 卜部 厚志, 前田 宜浩, 石澤 友浩, 廣瀬 亘, 小山内 信智, 山田 孝, 笠井 美青, 檜垣 大助, 風間 基樹, 千木良 雅弘, 渦岡 良介, 竹林 洋史, 木村 誇, 石丸 聡, 岡田 成幸, 内田 賢悦, 有村 幹治, 植松 武是, 多々納 裕一, 梶谷 義雄, 能島 暢呂, 田村 圭子, 中村 洋光, 戸松 誠 自然災害科学総合シンポジウム講演論文集 (56) 21 -26 2019年09月11日 [査読無し][通常論文]
     
    2019年9月11日(水), 於 : キャンパスプラザ京都 第1講義室「平成30年北海道胆振東部地震」とその災害に関する総合調査を実施した。震度7を記録した揺れにより, 同時多発斜面災害と, 北海道全域同時停電(ブラックアウト)が発生し, 複合的な災害となった。震源の深さは約37kmで, 大すべり域はそれより浅い20-25km付近であった。木造家屋の倒壊が多発したむかわ町市街では, 地盤構造による地震波の増幅が見られた。同時多発斜面崩壊は, 近隣の活火山の噴火による降下火砕堆積物が素因となった。札幌市内の地盤液状化地帯では, 極めて軟弱な谷埋盛土層が確認された。地震発生が未明であったことが, 建物倒壊による直接死が出なかったことに関係している可能性がある。ブラックアウトは, 社会経済活動に大きな影響を与えた。
  • 中村貴久, 桃谷尚嗣, 石川達也, 早野公敏 土木学会論文集 E1(舗装工学)(Web) 75 (1) 41‐52(J‐STAGE) -52 2019年 [査読無し][通常論文]
     
    <p> 鉄道バラスト軌道を支持する構造物の耐震設計および耐震対策が進むなか,バラスト軌道に対する耐震設計の整備とともに耐震対策の開発が求められている.既往の研究では,加振中に道床横抵抗力が低下し,レール軸力が作用している場合には,水平方向に残留変位が生じる場合があることがわかっている.本研究では,効果の高い座屈対策工を開発することを目的として,加振中に道床横抵抗力が低下するメカニズムを解明するため,バラスト軌道の小型模型を用いた振動台試験を行い,加振中のバラストの変形挙動を高速度カメラを用いて撮影し,PIVによる画像解析を行った.さらに,地震時における座屈対策工の道床横抵抗力を検討するため,バラスト軌道の実物大模型を用いた大型振動台試験を行った.</p>
  • Tatsuya Ishikawa, Srikrishnan Siva Subramanian, Tetsuya Tokoro Lecture Notes in Civil Engineering 28 467 -498 2019年01月01日 [査読無し][通常論文]
     
    © 2019, Springer Nature Singapore Pte Ltd. Climate change-induced large-scale natural hazards are problematic for confrontation. Many of the snowy cold regions of Japan, i.e. Hokkaido, experience multifaceted types of natural disasters, i.e. slope failures and debris flows due to abnormal weather and rainfall patterns which were never encountered in the past. In consideration of the change of extreme weather patterns in future, this study has attempted to develop a wide-area disaster risk assessment at first with introducing an early warning criterion for snowy cold regions and then by proposing and analysing the applicability of a wide-area slope failure analysis method. To this end, we have performed early warning and wide-area numerical modelling studies for various cases of soil slope failures in Hokkaido which shows new paths for the disaster mitigation.
  • Tomoyuki Aoyagi, Jiaqiang Yang, Shingo Matsutani, Tatsuya Ishikawa, Takahisa Nakamura, Yoshitsugu Momoya Lecture Notes in Civil Engineering 29 409 -422 2019年01月01日 [査読無し][通常論文]
     
    © Springer Nature Singapore Pte Ltd 2019. With time passing, the performance of railway ballasted track and road pavement gradually degrades along with the degradation in railroad ballast and base course layer. However, the Japanese design standard does not consider the age-related deterioration of ballasted track and asphalt pavement. To establish a rational maintenance method of aged ballasted track and road pavement, this study focused on the water retentivity. In this paper, a water retention test apparatus was newly developed to carry out water retention test for coarse granular materials subjected to freeze-thaw. The test samples are Toyoura sand, clean and fouled ballast, and new and aged crusher runs. First, the performance of the newly developed test apparatus was examined by comparing the test results of water retention tests of this paper with the past researches. Second, the influence of age-related degradation for coarse granular materials on the water retentivity was discussed by comparing the test results for aged test samples with the new ones. As a result, the following findings were obtained: (a) The developed test apparatus can carry out highly accurate water retention tests in a wide suction range and greatly shorten the testing time. (b) SWCC is seriously affected by the intrusion of fouling materials, regardless of the sample.
  • 青柳智之, 石川達也, 丸山記美雄, 上野千草 地盤工学会北海道支部技術報告集(CD-ROM) (59) ROMBUNNO.39 2019年01月 [査読無し][通常論文]
  • 西村聡, 石川達也, 磯部公一, 小松正宏, 蝦名浩二, 笹原啓佑 地盤工学会北海道支部技術報告集(CD-ROM) (59) ROMBUNNO.32 2019年01月 [査読無し][通常論文]
  • 廣瀬剛, 伊藤譲, 石川達也, 赤川敏, 所哲也, 大西有三 土木学会年次学術講演会講演概要集(CD-ROM) 73rd ROMBUNNO.III‐222 2018年08月01日 [査読無し][通常論文]
  • 石川達也, 川端伸一郎, 木幡行宏, 川村志麻 北海道地区自然災害科学資料センター報告 31 3‐30 -30 2018年03月31日 [査読無し][通常論文]
  • 森瑛, 石川達也, SUBRAMANIAN Srikrishnan Siva, THANH Nguyen Binh 地盤工学会北海道支部技術報告集(CD-ROM) (58) 105‐114 2018年01月 [査読無し][通常論文]
  • 青木亮介, 石川達也, 所哲也, LIN Tianshu 地盤工学会北海道支部技術報告集(CD-ROM) (58) 23‐30 2018年01月 [査読無し][通常論文]
  • 松谷真吾, 石川達也, 青柳智之, 中村貴久, 桃谷尚嗣 地盤工学会北海道支部技術報告集(CD-ROM) (58) 7‐16 2018年01月 [査読無し][通常論文]
  • 青柳智之, 石川達也, 丸山記美雄, 工藤静瑠 地盤工学会北海道支部技術報告集(CD-ROM) (58) 217‐224 2018年01月 [査読無し][通常論文]
  • 清水公陽, 磯部公一, 石川達也 地盤工学会北海道支部技術報告集(CD-ROM) (58) 301‐308 2018年01月 [査読無し][通常論文]
  • Toshihiro Morii, Tatsuya Ishikawa, Kaoru Kobayashi, Yoshinori Hanada, Kenta Muto Proceedings of the 7th China-Japan Geotechnical Symposium: New Advances in Geotechnical Engineering, CJGS 2018 2018-March 220 -226 2018年01月01日 [査読無し][通常論文]
     
    © 2018 China Communications Press Co. Ltd. All rights reserved. Capillary barrier (CB) is a tilting soil layer system which is composed of a finer soil layer underlain by a coarser soil layer. Water infiltrating into soil is suspended just above an interface between the soil layers and diverted downward along the interface. Because of this diversion of infiltration water, the CB has been employed in a top cover of waste landfills and mining wastes to reduce water infiltration into the protected waste materials. Water flow downward along the interface accumulates gradually its mass of flow due to continuous infiltration from the soil surface, and, at some length along the interface, water percolates into the coarser soil layer. A horizontal distance from the beginning of water flow to this point of percolation is called a diversion length of the CB, and is one of important parameters in designing structural dimensions and configuration of the CB system and in selecting a suitable combination of the finer and coarser soils. Shallow land waste repository, in which the top CB and bottom CB are placed to reduce infiltration due to rainfall and to divert percolating water through the protected waste material respectively, is proposed to isolate effectively a hazardous waste material or a very low level radioactive waste. A laboratory soil box test was conducted to investigate and estimate the diversion length, and a trial embankment was constructed in the field to investigate performance of the CB in the shallow land waste repository. The diversion length can be estimated with a practical accuracy based on saturated and unsaturated hydraulic properties of soils employed in the CB, inclination of the interface and infiltration rate expected in the field. Field observation of soil water movement in the test embankment shows excellent and stable diversion of infiltration water in the CB system.
  • T. Ishikawa, S. Matsutani, T. Tokoro, T. Nakamura, Y. Momoya Bearing Capacity of Roads, Railways and Airfields - Proceedings of the 10th International Conference on the Bearing Capacity of Roads, Railways and Airfields, BCRRA 2017 1817 -1825 2018年01月01日 [査読無し][通常論文]
     
    © 2017 Taylor & Francis Group, London. This paper examines the influence of parallel grading on the hydro-mechanical characteristics of unsaturated fouled ballast by conducting a series of triaxial compression tests and water retentivety tests on various fresh and fouled ballasts with parallel grading in unsaturated conditions. As the results, it was revealed that soil-water characteristic curves and relationships between degree of saturation and peak shear strength were seriously affected by intrusion of fouling materials into fresh ballast, and that the hydro-mechanical characteristics of unsaturated fouled ballast was influenced by the average grain size even if employing the parallel gradation of grain size distribution. These results indicate that for the precise evaluation of the mechanical property of unsaturated fouled ballast, it is important to carefully interpret the test results using the parallel grading geomaterials.
  • Biyanvilage Dareeju, Chaminda Gallage, Tatsuya Ishikawa, Manika Dhanasekar, Les Dawes Journal of GeoEngineering 13 161 -170 2018年01月01日 [査読無し][通常論文]
     
    © 2018 Journal of GeoEngineering. Cumulative plastic deformation characteristics of rail tracks under moving wheel loads are complex problems. Globally the rail industry is challenged by effective maintenance strategies to ensure safety of the rail track structures. Influence of particle size distributions (PSDs) on the cyclic cumulative plastic deformation of coarse materials in the rail track substructure layers under moving wheel load is not well understood. Conventional test approaches, namely the direct shear test, the cyclic single point load test, and the California bearing ratio test, cannot replicate the actual stress-strain state of coarse materials under moving wheel loads. The multi-ring shear apparatus, an improved torsional simple shear apparatus to replicate moving train wheel loading conditions, was used in this study. The PSDs of coarse materials were experimentally simulated through modifications to the mass portions of different glass beads. The moving wheel loads introduce higher plastic deformation and lower resilient modulus irrespective of the PSDs compared to cyclic single point load tests. Further study with three natural coarse materials (Toyoura sand and two ballast types) indicates that the cumulative plastic deformation has nonlinear relationships between the principal stress axis rotation and PSDs of the materials.
  • 青柳智之, 石川達也, 松谷真吾, 中村貴久, 木次谷一平 地盤工学研究発表会発表講演集(CD-ROM) 53rd ROMBUNNO.0594 2018年 [査読無し][通常論文]
  • 清水公陽, 磯部公一, 石川達也 地盤工学研究発表会発表講演集(CD-ROM) 53rd ROMBUNNO.1048 2018年 [査読無し][通常論文]
  • 細田充, 田中博文, 石川達也 構造工学論文集 A(CD-ROM) 63 (0) ROMBUNNO.4‐2 -181 2017年03月15日 [査読無し][通常論文]
     
    The rail corrugation on high rail often generates on ballast-less track, however its mechanism has been not known in detail yet. In this paper, first of all, we assumed that the track supporting stiffness under sleeper influenced the generation situation of high rail corrugation based on the results of the various field investigations. Then, we developed vehicle dynamic simulation models by means of multibody dynamics for verifying the influence of the track supporting stiffness. In addition, we simulated on-board measurement for verifying adequacy of analysis method. Finally, we examined influence of the track stiffness on the dynamic interaction between vehicle and track.
  • LAI Hao, LUO Bin, ISHIKAWA Tatsuya 地盤工学会北海道支部技術報告集(CD-ROM) (57) ROMBUNNO.3 2017年02月 [査読無し][通常論文]
  • OPON Joel Galupo, SIVA SUBRAMANIAN Srikrishnan, ISHIKAWA Tatsuya, ISOBE Koichi, SHIMIZU Yasuyuki 地盤工学会北海道支部技術報告集(CD-ROM) (57) ROMBUNNO.24 2017年02月 [査読無し][通常論文]
  • 瀬戸哲, 石川達也, BIYANVILAGE Dareeju, CHAMINDA Gallage 地盤工学会北海道支部技術報告集(CD-ROM) (57) ROMBUNNO.28 2017年02月 [査読無し][通常論文]
  • 木村洸太, 所哲也, 石川達也 地盤工学会北海道支部技術報告集(CD-ROM) (57) ROMBUNNO.7 2017年02月 [査読無し][通常論文]
  • 松谷真吾, 石川達也, 青柳智之, 中村貴久, 桃谷尚嗣 地盤工学会北海道支部技術報告集(CD-ROM) (57) ROMBUNNO.10 2017年02月 [査読無し][通常論文]
  • 所哲也, 金子治暉, 石川達也, SRIKRISHNAN Subrmanian Siva 地盤工学会北海道支部技術報告集(CD-ROM) (57) ROMBUNNO.34 2017年02月 [査読無し][通常論文]
  • 森瑛, THANH Nguyen Binh, 石川達也, 村山陽 地盤工学研究発表会発表講演集(CD-ROM) 52nd ROMBUNNO.0443 2017年 [査読無し][通常論文]
  • 青木亮介, 所哲也, 石川達也 地盤工学研究発表会発表講演集(CD-ROM) 52nd ROMBUNNO.0551 2017年 [査読無し][通常論文]
  • 青柳智之, 石川達也, 松谷慎吾, 中村貴久, 桃谷尚嗣 地盤工学研究発表会発表講演集(CD-ROM) 52nd ROMBUNNO.0457 2017年 [査読無し][通常論文]
  • 松谷真吾, 石川達也, 青柳智之, 中村貴久, 桃谷尚嗣 地盤工学研究発表会発表講演集(CD-ROM) 52nd ROMBUNNO.0553 2017年 [査読無し][通常論文]
  • Siva Subramanian Srikrishnan, Ishikawa Tatsuya, Tokoro Tetsuya, Kusunoki Fumiya Japanese Geotechnical Society Special Publication (Web) 5 (2) 135‐140(J‐STAGE) -140 2017年 [査読無し][通常論文]
     
    <p>In seasonal cold regions like Hokkaido, the soil surface up to a shallow depth is frozen during the winter. An earthquake during the freezing period and thawing period may cause severe disasters i.e. slope failures induced by the combined effects of seismicity and snow melt water. The influences of freezing conditions on the seismic behaviour of soil need to be studied elaborately. In this study, a series of shaking table tests were performed with frozen surface layer and numerical analysis has been performed to simulate the seismic behaviour of soil under the frozen surface state. The numerical analysis has been done based on the series of shaking table tests performed under two different conditions i.e. without a frozen soil surface layer and with 10 cm frozen soil at the surface. Loose density (Dr=30~35 %) and high density (Dr=75~80 %) Toyoura sand have been used to study the liquefaction behaviour. Different liquefaction behaviour is observed when considering surface frozen conditions under both loose and high relative densities of soil. Through the shaking table tests and numerical simulations performed, it is clear that the frozen surface layer severely affects the seismic response of the soil and if these conditions prevail on a soil slope during an earthquake, a sliding slope failure causing the movement of frozen soil layer may occur conceivably. </p>
  • Akira Mori, Srikrishna Siva Subramanian, Tatsuya Ishikawa, Masahiro Komatsu PROCEEDINGS OF THE INTERNATIONAL SCIENTIFIC CONFERENCE TRANSPORTATION GEOTECHNICS AND GEOECOLOGY (TGG-2017) 189 533 -538 2017年 [査読有り][通常論文]
     
    In cold regions, frequent incidents of soil slope failures occur due to snowmelt and rainfall. These failures are triggered by an increase in the degree of saturation of soil due to infiltration of water derived from rainfall and snowmelt. This study investigates a soil slope failure occurred on November 27, 2015 at a cut slope of an expressway in Hokkaido, Japan. The soil slope failure is investigated using a recommended stability assessment approach considering non-isothermal coupled seepage flow simulation followed by a limit equilibrium slope stability analysis. It is concluded that at the thawing period, the slope stability is affected by rainfall and snowmelt water infiltration and later in November the failure happened due to overflow of water from a drainage ditch. (C) 2017 Published by Elsevier Ltd.
  • Tetsuya Tokoro, Tatsuya Ishikawa, Srikrishnan Siva Subramanian ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering 2017-September 1597 -1600 2017年01月01日 [査読無し][通常論文]
     
    © 2017 19th ICSMGE Secretariat. All rights reserved. The objective of this study is to clarify the mechanism of geotechnical disasters due to the earthquake during winter. Shaking table tests were conducted for the soil model with the frozen surface layer to reveal the dynamic behavior. Temperature-controlled direct shear tests were also conducted using bilayer specimen composed of unfrozen and frozen soil to evaluate the strength characteristics of the boundary layer between unfrozen and frozen soil. Based on the test results, under the frozen surface condition, different dynamic behaviors from unfrozen condition were observed. The excess pore water pressure distribution was uniform in unfrozen soil because of the high permeability of sand and the existence of the surface frozen layer. Furthermore, liquefaction occurs only in the superficial layer of unfrozen layer and liquefaction strength under surface frozen condition rises in comparison with the unfrozen condition. It is assumed that increment in the surface friction between frozen and unfrozen soil, obtained by the direct shear test, reduces the movement of soil particles.
  • Erol Tutumluer, Tatsuya Ishikawa ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering 2017-September 1325 -1332 2017年01月01日 [査読無し][通常論文]
     
    © 2017 19th ICSMGE Secretariat. All rights reserved. Today's needs of urban transportation including roads, railways, airports and harbours demand significant resources for infrastructure development in view of rapid and efficient public and commercial (freight) services. In most cases, authorities have had difficulties in meeting these service demands due to the rapidly growing public, industrial, mining and agricultural sectors in many parts of the world. In order to maximise efficiency and to reduce the costs of maintenance, sound technical knowledge is required. This general report presents major technical advancements around the globe encompassing 31 articles from 19 countries and it is classified into 3 sessions, namely: "Rail session", "Pavement session" and others.
  • Srikrishnan Siva Subramanian, Tatsuya Ishikawa, Tetsuya Tokoro ICSMGE 2017 - 19th International Conference on Soil Mechanics and Geotechnical Engineering 2017-September 2203 -2206 2017年01月01日 [査読無し][通常論文]
     
    © 2017 19th ICSMGE Secretariat. All rights reserved. Soil slope failures are often triggered by snowmelt water infiltration and rainfall infiltration in seasonal cold regions like Hokkaido, Japan. The water content fluctuation of a soil slope in seasonal cold regions is governed by the freeze-thaw action and infiltration resulting from snowmelt water and rainfall. In this study, to scrutinise the climatic influence which has a profound effect on unsaturated soil slope stability in seasonal cold regions, a series of parametric numerical simulation studies have been performed for an embankment slope failure case example based on a slope stability assessment approach. As a result, it is found that the snowmelt water infiltration and freeze-thaw action have very significant impacts on soil slope stability and for the assessment of the long-term stability of unsaturated soil slopes these phenomena should be considered. In addition, to predict the snowmelt induced soil slope failures, an early warning/prediction criterion is recommended which considers the short-term and long-term snowmelt/rainfall infiltration effects. The new early warning criterion applied and tested using the case example performs well under different climatic influences and can be used for the prediction and early warning of snowmelt induced soil slope failures in seasonal cold regions.
  • Jeffrey L. Lee, Dar Hao Chen, Tatsuya Ishikawa International Journal of Pavement Research and Technology 9 (6) 403 -404 2016年11月01日 [査読無し][通常論文]
  • 石川 達也 基礎工 = The foundation engineering & equipment, monthly : 土木・建築基礎工事と機材の専門誌 44 (11) 6 -11 2016年11月 [査読無し][通常論文]
  • 廣瀬剛, 廣瀬剛, 伊藤譲, 石川達也, 赤川敏, 所哲也, 大西有三 土木学会年次学術講演会講演概要集(CD-ROM) 71st ROMBUNNO.III‐314 2016年08月01日 [査読無し][通常論文]
  • 伊藤譲, 廣瀬剛, 廣瀬剛, 石川達也, 所哲也, 赤川敏, 大西有三 土木学会年次学術講演会講演概要集(CD-ROM) 71st ROMBUNNO.III‐315 2016年08月01日 [査読無し][通常論文]
  • NGUYEN Binh Thanh, ISHIKAWA Tatsuya, SIVA SUBRAMANIAN Srikrishnan, YOKOHAMA Shoji, TOKORO Tetsuya 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.40 2016年01月 [査読無し][通常論文]
  • SIVA SUBRAMANIAN Srikrishnan, ISHIKAWA Tatsuya, TOKORO Tetsuya, KUSUNOKI Fumiya 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.39 2016年01月 [査読無し][通常論文]
  • 松谷真吾, 石川達也, 福真治, 中村貴久, 桃谷尚嗣 地盤工学研究発表会発表講演集(CD-ROM) 51st ROMBUNNO.0493 2016年 [査読無し][通常論文]
  • 石川達也, 桃谷尚嗣, 早野公敏 地盤工学研究発表会発表講演集(CD-ROM) 51st ROMBUNNO.0036 2016年 [査読無し][通常論文]
  • 石川達也, 桃谷尚嗣, 中村貴久, 早野公敏, 河井勝之, 小関裕二, 高橋茂樹, 廣津栄三郎 地盤工学研究発表会発表講演集(CD-ROM) 51st ROMBUNNO.0492 2016年 [査読無し][通常論文]
  • 森瑛, 石川達也, THANH Nguyen Binh, 所哲也 地盤工学研究発表会発表講演集(CD-ROM) 51st ROMBUNNO.0484 2016年 [査読無し][通常論文]
  • 木村洸太, 所哲也, 石川達也 地盤工学研究発表会発表講演集(CD-ROM) 51st ROMBUNNO.0434 2016年 [査読無し][通常論文]
  • 木次谷一平, 中村貴久, 桃谷尚嗣, 石川達也 地盤工学研究発表会発表講演集(CD-ROM) 51st ROMBUNNO.0494 2016年 [査読無し][通常論文]
  • 石川達也, 松谷真吾, 所哲也, 中村貴久, 桃谷尚嗣 土木学会論文集 E1(舗装工学)(Web) 72 (3) I_151‐I_158(J‐STAGE) 2016年 [査読無し][通常論文]
  • 廣瀬剛, 伊藤譲, 石川達也, 赤川敏, 所哲也, 大西有三, 上田保司 地盤改良シンポジウム論文集(CD-ROM) 12th ROMBUNNO.3‐3 2016年 [査読無し][通常論文]
  • 福真治, 石川達也, 松谷真吾, 中村貴久, 桃谷尚嗣 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.15 2016年01月 [査読無し][通常論文]
  • 所哲也, 楠章哉, 石川達也, SIVA SRIKRISHNAN Subrmanian 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.38 2016年01月 [査読無し][通常論文]
  • 川端伸一郎, 川尻峻三, 石川達也 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.45 2016年01月 [査読無し][通常論文]
  • 木村充宏, 石川達也, 中田隆文, SIVA SUBRMANIAN Srikrishnan, NGUYEN Binh, Thanh, 森暎 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.27 2016年01月 [査読無し][通常論文]
  • 山添稜也, 石川達也, 伊藤譲 地盤工学会北海道支部技術報告集(CD-ROM) (56) ROMBUNNO.41 2016年01月 [査読無し][通常論文]
  • X. Y. Zheng, T. Ishikawa, T. Tokoro UNSATURATED SOIL MECHANICS-FROM THEORY TO PRACTICE 275 -280 2016年 [査読無し][通常論文]
     
    Slope failures or landslides on soil ground formed by volcanic soils occur frequently in Hokkaido, Japan. The objective of this paper is to examine the effect of fine particles run off on the shear strength of volcanic coarse-grained soils under unsaturated condition. An unsaturated triaxial apparatus was used and a series of monotonic triaxial compression tests for a crushable volcanic coarse-grained soil from which fine particles have been partially removed previously were performed under various degree of saturation. By comparing test results to the previous research, it has been known that the shortage in fine particles have a strong effect on the shear strength of volcanic coarse-grained soil in both saturated and unsaturated conditions. With fine particles run off, the shear strength decreased sharply as if it has suffered a deterioration process.
  • Chaminda Gallage, Biyanvilage Dareeju, Manika Dhanasekar, Tatsuya Ishikawa ADVANCES IN TRANSPORTATION GEOTECHNICS III 143 252 -259 2016年 [査読無し][通常論文]
     
    Precise assessment of cyclic plastic deformation of rail track subgrade is essential in designing cost effective rail tracks. Plastic deformation of rail tracks is often underestimated due to the omission of effects of principal stress axis rotation and water content on subgrade deformation. Moisture content of rail track subgrade is influenced by infiltration, seasonal ground water table variation and climate changes. To understand the influence of principal stress axis rotation and moisture content on the plastic deformation of soil, a series of cyclic moving wheel loading tests and cyclic triaxial compression tests were performed on unsaturated Toyoura sand, using a modified multi-ring shear apparatus. Results show that the presence of water in sand affects the cyclic plastic deformation of subgrade of rail tracks, significantly. The subgrade water content variation combined with the principal stress axis rotation further increases the accumulation of the cyclic plastic deformation of subgrade under moving wheel loads. Experimental results further conclude that the conventional experimental methods are unable to accurately assess the rail track deterioration process introduced by water content of rail track subgrade under repeated moving wheel load and highlight the requirements of realistic test methods such as the cyclic moving load multi-ring shear test, the cyclic hollow cylindrical test, or the model test in predicting rail track deterioration process of unsaturated subgrade under moving wheel loads.
  • S. Seto, T. Ishikawa, B. Dareeju, C. Gallage, B. Luo Civil-Comp Proceedings 110 2016年01月01日 [査読無し][通常論文]
     
    © Civil-Comp Press, 2016. The research presented in this paper includes an experimental study to evaluate the synergistic effects of principal stress axis rotation and change in water content on the mechanical behavior of a railway roadbed. This is in order to examine the mechanism of cyclic plastic deformation of railway roadbed subjected to cyclic moving wheel loads at a ballasted track. Three types of tests, namely a static torsional shear test, a single-point loading method and a moving-wheel loading method, were mainly performed with mixed soil which was composed of silicabentonite sand (silica 74.7%, bentonite 25.3%) and Toyoura sand subject to an air-dried condition and an unsaturated condition. Based on the test results, the influence of water content and moving-wheel loads on the deformation-strength characteristics of geomaterials were examined. The results revealed that the difference in the loading method and water content has a considerable influence on the cyclic plastic deformation of the railway roadbed. This leads to the conclusion that for the precise prediction of the long-term performance of substructures for a ballasted track under cyclic moving-wheel loads, it is important to take into account the synergistic effects of principal stress axis rotation and water content change on the cyclic plastic deformation characteristics of the railway roadbed.
  • 廣瀬剛, 伊藤譲, 石川達也, 赤川敏, 所哲也, 大西有三, 上田保司 土木学会年次学術講演会講演概要集(CD-ROM) 70th ROMBUNNO.III-281 2015年08月01日 [査読無し][通常論文]
  • 山添稜也, 石川達也, 伊藤譲 土木学会年次学術講演会講演概要集(CD-ROM) 70th ROMBUNNO.III-276 2015年08月01日 [査読無し][通常論文]
  • 所哲也, 石川達也, 赤川敏, 伊藤譲, 佐々木飛翔, 大西有三, 廣瀬剛, 上田保司 土木学会年次学術講演会講演概要集(CD-ROM) 70th ROMBUNNO.III-279 2015年08月01日 [査読無し][通常論文]
  • 廣瀬剛, 伊藤譲, 石川達也, 赤川敏, 所哲也, 大西有三 土木学会関西支部年次学術講演会講演概要集(CD-ROM) 2015 ROMBUNNO.III-13 2015年05月07日 [査読無し][通常論文]
  • SIVA SUBRAMANIAN Srikrishnan, ISHIKAWA Tatsuya, TOKORO Tetsuya 地盤工学会北海道支部技術報告集(CD-ROM) (55) ROMBUNNO.36 2015年01月 [査読無し][通常論文]
  • Biyanvilage Dareeju, Chaminda Gallage, Manika Dhanasekar, Tatsuya Ishikawa 15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2015: New Innovations and Sustainability 2 (46) 1619 -1622 2015年 [査読無し][通常論文]
     
    Cyclic plastic deformation of subgrade and other engineered layers is generally not taken into account in the design of railway bridge transition zones, although the plastic deformation is the governing factor of frequent track deterioration. Actual stress behavior of fine grained subgrade/embankment layers under train traffic is, however, difficult to replicate using the conventional laboratory test apparatus and techniques. A new type of torsional simple shear apparatus, known as multi-ring shear apparatus, was therefore developed to evaluate the actual stress state and the corresponding cyclic plastic deformation characteristics of subgrade materials under moving wheel load conditions. Multi-ring shear test results has been validated using a theoretical model test results the capability of the multi-ring shear apparatus for replicating the cyclic plastic deformation characteristics of subgrade under moving train wheel load conditions is thus established. This paper describes the effects of principal stress rotation (PSR) of the subgrade materials to the cyclic plastic deformation in a railroad and impacts of testing methods in evaluating the influence of principal stress rotation to the track deterioration of rail track.
  • Tatsuya Ishikawa, Ippei Kijiya, Tetsuya Tokoro, Masaru Sato 15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2015: New Innovations and Sustainability 2 (13) 531 -536 2015年 [査読無し][通常論文]
     
    This paper presents numerical simulations on frost heave phenomenon observed at the earth structures and pavement structures using a coupled thermo-hydro-mechanical (THM) FE analysis, which can consider the change in deformation-strength characteristics and water retention-permeability characteristics due to freeze-thaw actions, and can reproduce frost-heave of soils under unsaturated conditions based on the results of frost heave tests. In order to evaluate the influences of freeze-thaw action on the interaction between frost-susceptible soil ground and structures quantitatively, a series of numerical simulations for cut slope and pavement structure subjected to freeze-thaw actions were performed. As the results, it was revealed that the coupled FE analysis employed in this study has a sufficient applicability to the precise prediction for the frost-heave behavior of soil ground, and that the frost-heave behavior has a considerable influence on the deformation and failure of earth structures in terms of the deformation and stress state of structures by examining the relation between frost heave and frost penetration depth.
  • Ishikawa Tatsuya, Tokoro Tetsuya, Seiichi Miura Japanese Geotechnical Society Special Publication 1 (1) 1 -20 2015年 [査読無し][通常論文]
     
    This study examines the mechanism of the geohazards occurred at a volcanic soil slope in cold regions and its influencing factors in consideration of the effects of freeze-thaw actions on the physical properties, the water retention-permeability characteristics, and the deformation-strength characteristics of volcanic soils from the viewpoint of both experimental study and analytical study. To this end, we performed the long-term field measurement, model tests, laboratory element tests, and numerical simulations by taking volcanic soil slope subjected to freeze-thaw actions. As the results, this study revealed that there is a difference in the slope failure mechanism between cold region and warm-temperate region, and that freeze-thaw actions seriously influence thermo-hydro-mechanical behaviour of crushable volcanic coarse-grained soil slope under unsaturated condition even if the soil is a non-frost-susceptible geomaterial. Furthermore, this study clarified the mechanism, the endogenous factors, and the exogenous factors of the slope failure for volcanic soil ground in Hokkaido in comparison with the slope failure in warm-temperate regions.
  • 瀬戸哲, 石川達也, DAREEJU Biyanvilage, GALLAGE Chaminda 地盤工学研究発表会発表講演集(CD-ROM) 50th ROMBUNNO.605 2015年 [査読無し][通常論文]
  • 伊藤譲, 石川達也, 赤川敏, 所哲也, 大西有三, 上田保司, 廣瀬剛 地盤工学研究発表会発表講演集(CD-ROM) 50th ROMBUNNO.448 2015年 [査読無し][通常論文]
  • 木村充宏, 中田隆文, 石川達也 土木学会北海道支部論文報告集(CD-ROM) (71) ROMBUNNO.C-03 2015年01月 [査読無し][通常論文]
  • 高橋優紀, 石川達也, 所哲也, 木次谷一平, 浦崎拓人 地盤工学会北海道支部技術報告集(CD-ROM) (55) ROMBUNNO.28 2015年01月 [査読無し][通常論文]
  • 所哲也, 石川達也 地盤工学会北海道支部技術報告集(CD-ROM) (55) ROMBUNNO.31 2015年01月 [査読無し][通常論文]
  • 木次谷一平, 石川達也, 所哲也, 里優 地盤工学会北海道支部技術報告集(CD-ROM) (55) ROMBUNNO.34 2015年01月 [査読無し][通常論文]
  • 山添稜也, 石川達也, 高橋優紀, 浦崎拓人 地盤工学会北海道支部技術報告集(CD-ROM) (55) ROMBUNNO.35 2015年01月 [査読無し][通常論文]
  • Xiaoyi Zheng, Tatsuya Ishikawa, Tetsuya Tokoro 6th Japan-China Geotechnical Symposium, SJGS 2015 1 (7) 11 -16 2015年 [査読無し][通常論文]
     
    In Hokkaido, Japan, over 40% area has been covered by volcanic coarse-grained soils. Due to the extreme weather in Hokkaido, snowfall always reaches several meters. After winter, a large amount of snow melts into water simultaneously, and at the same time permeated into ground rapidly and continuously. Fine particles contained in soil, therefore, will be carried out of soil structure by water. Changes in soil structure should be expected. The main purpose of this paper is to examine influences of fine particles run off on the shear behavior and Soil-Water Characteristic Curve, SWCC, which plays a very important role in the determination of unsaturated soil property function, of the volcanic coarse-grained soil under unsaturated condition. A series of triaxial compression tests and soil-water characteristic test were performed for volcanic coarse-grained soil from which fine particles were removed by water flow previously. The experimental results show that the shear strength of volcanic coarse-grained soil decreases substantially under both saturated condition and unsaturated condition when fine content was removed. Fine particles run off also gives a strong influence to soil-water characteristic curve. It causes a rightward shift in soil-water characteristic curve.
  • Srikrishnan Siva Subramanian, Tatsuya Ishikawa, Shoji Yokohama, Tetsuya Tokoro 6th Japan-China Geotechnical Symposium, SJGS 2015 1 (7) 5 -10 2015年 [査読無し][通常論文]
     
    Slope instability issues due to freeze-thaw action, rainfall and seismicity are common in cold regions like Hokkaido. It is essential to study the varied impacts of temperature difference and infiltration due to rainfall on soil slope stability. The main objective of this study is to find a suitable slope stability assessment method considering the effects of freeze-thaw and rainfall. An embankment slope failure study performed by previous researchers has been numerically simulated. A modelling methodology to perform freeze-thaw, seepage and limit equilibrium slope stability analysis has been adopted and followed. Crucial parameters for slope stability i.e. initial moisture content, moisture content distribution during failure were obtained from the simulation and then compared with the measurement data. The numerical results compared with the measured data provide rational satisfaction and demonstrate the applicability of the software code in order to predict the stability of slope. The numerical modelling approach used in this study is found useful in analysing the rational stability of soil slopes and to simulate the moisture content distribution of slopes subjected to freeze-thaw and rainfall infiltration.
  • T. Ishikawa, I. Kijiya, T. Tokoro, M. Sato Computer Methods and Recent Advances in Geomechanics 415 -420 2015年 [査読無し][通常論文]
     
    This study proposes a new numerical model to simulate the Thermo-Hydro-Mechanical (THM) behavior of saturated and unsaturated soils suffered from one-dimensional freeze-thawing. First, a coupled THM FE analysis, which can consider the change in deformation-strength and water retention-permeability characteristics due to freeze-thaw actions, was newly developed. It also can reproduce frost heave phenomenon of soils under saturated and unsaturated conditions based on the results of frost susceptibility tests. Subsequently, a series of numerical simulations on frost heave tests of a soil specimen was conducted by the proposed FE analysis, and the analytical results were compared with experimental results to examine the applicability of the coupled FE analysis. As the result, it was revealed that the coupled FE analysis proposed in this study has valuable advantages of excellent applicability to the precise prediction method for the thermal-hydro-mechanical behavior of frost-susceptible soils during freeze-thaw.
  • T. Ishikawa, S. Miura, T. Tokoro Geomechanics from Micro to Macro, Vols I and II 2 1415 -1420 2015年 [査読無し][通常論文]
     
    This study examines the effect of freeze-thaw actions and wet-dry cycles on the particle crushability and water retentivity of volcanic coarse-grained soils. A series of slaking tests for a cylindrical specimen made of two volcanic coarse-grained soils, which had different degree of particle crushability from each other, was performed under various freeze-thaw sequences. The dependency of the degree of particle breakage on freeze-thaw actions, the influences of the change in particle shape and the increase in fines content on the water retentivity were examined by performing slaking tests, sieve analysis and particle image analysis. Test results showed that particle breakage of non-frost susceptible volcanic coarse-grained soils increases by freeze-thaw actions and wet-dry cycles, and that shape change with the grain refining of volcanic soil particles due to freeze-thaw actions and wet-dry cycles causes a gradual fluctuation in the water retentivity.
  • Tatsuya Ishikawa, Seiichi Miura, Etsuo Sekine Transportation Geotechnics 1 (4) 157 -170 2014年12月01日 [査読無し][通常論文]
     
    This study examines a simplified and practical prediction method for the cumulative residual settlement of ballasted track under repeated train passages, and the applicability and usefulness of the proposed method are discussed by comparing the experimental results of cyclic loading tests of model ballasted track structures with the analytical results. As the results, this study proposed a new analytical procedure with iterative calculation by linear elastic Finite Element (FE) analysis, which can evaluate the effects of continuous rotation of principal stress axis due to moving-wheel loads by taking into consideration the cumulative strain characteristics of ballast obtained from laboratory element tests such as multi-ring shear tests adopting the moving-wheel loading method in terms of the practical use. In addition, it was revealed that when laboratory element tests with high accuracy was conducted under experimental conditions similar to the actual phenomena in order to grasp the cumulative strain characteristics of ballast and then plastic deformation analysis was performed based on the findings above, the proposed analytical procedure could roughly estimate the cyclic plastic deformation of railroad ballast under repeated moving-wheel loads even with a simple linear elastic FE analysis. These findings confirm sufficient applicability of the proposed analytical procedure to the estimation of the cumulative residual settlement observed at ballasted track structures subjected to repeated train passages.
  • 石川達也, 桃谷尚嗣 地盤工学シンポジウム論文集(CD-ROM) 59th ROMBUNNO.19‐3 -622 2014年11月27日 [査読無し][通常論文]
  • 青木亮介, 所哲也, 石川達也, 白井翔也, 中村努 土木学会年次学術講演会講演概要集(CD-ROM) 69th ROMBUNNO.III-127 2014年08月01日 [査読無し][通常論文]
  • 石川 達也 地盤工学会誌 62 (3) 2014年03月01日 [査読無し][通常論文]
  • 石川達也, 木次谷一平, 所哲也, 赤川敏 地盤工学研究発表会発表講演集(CD-ROM) 49th ROMBUNNO.429 2014年 [査読無し][通常論文]
  • 所哲也, 石川達也, 白井翔也, 中村努 地盤工学研究発表会発表講演集(CD-ROM) 49th ROMBUNNO.218 2014年 [査読無し][通常論文]
  • 高橋優紀, 山添稜也, 石川達也, 所哲也 地盤工学研究発表会発表講演集(CD-ROM) 49th ROMBUNNO.427 2014年 [査読無し][通常論文]
  • 木次谷一平, 石川達也, 所哲也, 里優 地盤工学会北海道支部技術報告集 (54) 65 -68 2014年01月 [査読無し][通常論文]
  • Yuan Zhang, Tatsuya Ishikawa, Tetsuya Tokoro, Tomoyoshi Nishimura Transportation Geotechnics 1 (2) 74 -89 2014年 [査読無し][通常論文]
     
    The aim of this study is to clarify strength characteristics of a subbase course material changed due to the degree of saturation and the strain rate. A series of monotonic triaxial compression tests was carried out under desired unsaturated and strain rate conditions using a medium-size triaxial compression apparatus. The test results indicate that the degree of saturation can significantly affect shear behaviors of the subbase course material in terms of the shear strength and deformability. On the other hand, the triaxial compression tests with the strain rate of 0.5%/min were conducted as well as those with 0.05%/min, which has been usually employed. The experimental results show that the mechanical behavior of the subbase course material is susceptible to the strain rate, and such relations can vary depending on the degree of saturation in shear. Furthermore, change in the strength parameters such as the total internal friction angle and the total cohesion resulting from the degree of saturation and the strain rate effects will be discussed. The calculation results show that the effects of degree of saturation and strain rate on the total internal friction angle appear to be negligible, while the total cohesion can be affected by the degree of saturation and the strain rate. More specifically, the failure envelope for the subbase course material is nonlinear under the low suction ranges. Therefore, the failure surface drawn through the failure envelope with respect to the matric suction is curved surface. The failure surface for unsaturated specimens with higher strain rate is located above that with lower strain rate. © 2014 Elsevier Ltd.
  • T. Tokoro, S. Shirai, T. Nakamura, T. Ishikawa UNSATURATED SOILS: RESEARCH & APPLICATIONS, VOLS 1 AND 2 2 1709 -1714 2014年 [査読無し][通常論文]
     
    The purpose of this study is to clarify the soils thermal conductivity dependency on water content. In this study, thermal conductivity tests were conducted for three types of soils under different moisture content using a thermal probe method. Water retention tests were also carried out in order to examine the effect of moisture content in the thermal conductivity of soils. Based on experimental results, it was revealed that soils thermal conductivity dependency on water content differed depending on the water retentivity characteristic of soils. The relationships between moisture content and thermal conductivity in the three types of soils are not linear, and it was observed an inflection point in each relationship. This indicates that thermal conductivity of soils depends on whether pore water, which contributes to conduct heat, is structurally continuous. Therefore, soils thermal conductivity dependency in water content can be explained by the structural configuration of pore water in the soils.
  • T. Ishikawa, T. Tokoro, D. Nakamura, S. Yamashita UNSATURATED SOILS: RESEARCH & APPLICATIONS, VOLS 1 AND 2 2 1189 -1195 2014年 [査読無し][通常論文]
     
    The objective of this study is to propose a laboratory element test for evaluating the air-permeability of unsaturated soils subjected to freeze-thaw action and to examine the effects of freeze-thawing and moisture content on air-permeability of unsaturated soils. This study develops a new test apparatus and perform a series of air-permeability tests for unsaturated soils under various freeze-thaw histories and moisture contents. As the results, it was revealed that the test device could evaluate air-permeability of geomaterials. Besides, it was recognized that though the difference in coefficient of air permeability before and after freeze-thaw were not observed in non-frost susceptible sand, the air-permeability of frost susceptible volcanic cohesive soil differs according to the moisture content and freezing rate. This indicates that the freeze-thaw action has strong influences on the air-permeability of frost susceptible geomaterials in unsaturated condition.
  • Tatsuya Ishikawa, Tetsuya Tokoro Springer Series in Geomechanics and Geoengineering 3 143 -148 2013年10月28日 [査読無し][通常論文]
     
    The objective of this study is to evaluate the effect of freeze-thaw action on the strength and water retention-permeability characteristics of crushable volcanic coarse-grained soils in unsaturated conditions. A series of triaxial compression tests, water retention tests and permeability tests were performed for volcanic coarse-grained soils under different freeze-thaw histories. Test results showed that the particle breakage caused by the freeze-thaw action made the shear strength in unsaturated conditions decrease and the water retentivity increase, while not affecting the permeability. These indicate that the freeze-thaw action has strong influences on the hydro-mechanical characteristics of a crushable volcanic coarse-grained soil in unsaturated conditions even if the soil lacks in frostsusceptibility. © Springer-Verlag Berlin Heidelberg 2013.
  • 白井翔也, 所哲也, 石川達也, 中村努 土木学会年次学術講演会講演概要集(CD-ROM) 68th ROMBUNNO.III-098 2013年08月01日 [査読無し][通常論文]
  • 川端伸一郎, 亀山修一, 石川達也 舗装 48 (7) 7 -11 2013年07月01日 [査読無し][通常論文]
  • 川端 伸一郎, 亀山 修一, 石川 達也 舗装 48 (7) 7 -11 2013年07月 [査読無し][通常論文]
  • ZHANG Yuan, ISHIKAWA Tatsuya, HAMAURA Tetsukazu, TOKORO Tesuya 地盤工学会北海道支部技術報告集 (53) 119 -122 2013年01月 [査読無し][通常論文]
  • 木次谷一平, 石川達也, 所哲也 地盤工学研究発表会発表講演集(CD-ROM) 48th ROMBUNNO.522 2013年 [査読無し][通常論文]
  • 川端伸一郎, 石川達也, 亀山修一 地盤工学研究発表会発表講演集(CD-ROM) 48th ROMBUNNO.519 2013年 [査読無し][通常論文]
  • 石川達也, 張媛, 川端伸一郎, 亀山修一, 所哲也 土木学会論文集 E1(舗装工学)(Web) 69 (3) I.207-I.214 (J-STAGE) -214 2013年 [査読無し][通常論文]
  • 石川達也, 木次谷一平, 所哲也, 里優 地盤工学会北海道支部技術報告集 (53) 231 -240 2013年01月 [査読無し][通常論文]
  • 所哲也, 白井翔也, 石川達也, 中村努 地盤工学会北海道支部技術報告集 (53) 191 -194 2013年01月 [査読無し][通常論文]
  • 山本隼央, 石川達也, 山下聡, 中村大, 所哲也 地盤工学会北海道支部技術報告集 (53) 11 -20 2013年01月 [査読無し][通常論文]
  • 木次谷一平, 石川達也, 所哲也 地盤工学会北海道支部技術報告集 (53) 255 -262 2013年01月 [査読無し][通常論文]
  • 川端伸一郎, 佐藤厚子, 石川達也 地盤工学会北海道支部技術報告集 (53) 263 -270 2013年01月 [査読無し][通常論文]
  • T. Ishikawa, Y. Zhang, S. Kawabata, S. Kameyama, T. Tokoro, T. Ono 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013 2 1287 -1290 2013年01月01日 [査読無し][通常論文]
     
    This paper examines the effects of freeze-Thaw and water content on the deformation-strength properties of subbase course materials to evaluate the mechanical behavior of granular base in cold regions. CBR tests of freeze-Thawed subbase course materials under various water contents, and the resilient modulus tests in unsaturated condition were conducted using two newly developed test apparatuses. Moreover, these results were compared with long-Term field measurement at a model pavement structure, including FWD tests. As the results, it was revealed that the deformation-strength characteristics of unbound granular base course materials deteriorate due to freeze-Thaw and increment of the water content in thawing season. This indicates that the freeze-Thaw of granular base has a strong influence on the fatigue life of pavement structures.
  • Yuan Zhang, Yuan Zhang, Tatsuya Ishikawa, Tatsuya Ishikawa, Tetsuya Tokoro, Satoru Shibuya Springer Series in Geomechanics and Geoengineering 501 -506 2013年01月01日 [査読無し][通常論文]
     
    The objective of this paper is to examine the influences of moisture content, loading speed, and degree of compaction on the shear behavior of compacted sandy soil under unsaturated conditions. A series of triaxial compression tests with various experimental conditions were carried out by using triaxial apparatus for unsaturated soil. The test results show that the shear strength of unsaturated soil decreases with the increase in moisture content and increases due to increment of loading speed. The effect of degree of compaction is also discussed. The results reveal that moisture content, loading speed, and degree of compaction have strong influences on the shear behavior of unsaturated sandy soil. © Springer-Verlag Berlin Heidelberg 2013.
  • T. Kawaguchi, D. Nakamura, S. Yamashita, S. Yamasaki, T. Ishikawa CHALLENGES AND INNOVATIONS IN GEOTECHNICS: PROCEEDINGS OF THE 18TH INTERNATIONAL CONFERENCE ON SOIL MECHANICS AND GEOTECHNICAL ENGINEERING, VOL 1 1 357 -360 2013年 [査読無し][通常論文]
     
    In cold and snowy areas, surface soils on slopes often move downward especially in early spring. Its moving caused by repeated freeze-thaw cycles. If we properly evaluate slope stabilities and carry out effective slope protection works, we should understand variations of strengths, stiffnesses. permeabilities, and so on in the cycles. By the way, it is known that repeated freeze thaw cycles make ice lenses within surface soil. They spread parallel to ground surface so they are arranged parallel to shear stress on the slope. In this study we carried out frost heave tests that obtained changes of the void ratio and permeability in the cycle of freezing and thawing, direct box shear tests that obtained strength-deformation characteristics in the cycles, and the bender element tests that also obtained velocities of shear waves with vertical and horizontal propagation in the cycles. Then we conclude that the formation of ice lenses made parallel to shear stress is important for mechanical properties of surface soils.
  • A. Inam, T. Ishikawa, S. Miura 5th Asia-Pacific Conference on Unsaturated Soils 2012 2 516 -521 2012年11月27日 [査読無し][通常論文]
     
    This research paper proposes a new testing method to determine cyclic deformation characteristics of unsaturated granular material, and accordingly examines the effect of moisture content under moving wheel loads. A series of laboratory element test using multi-ring shear apparatus, which can consider change in direction of principal stress axis like traffic loads in real condition, were carried out on granular material under different moisture contents. Results show that, moisture content has obvious effect on shear behavior of granular material and also explain that cyclic deformation increases due to rotation of principal stress axis. Results further show that, water content has a great influence on the cyclic plastic deformation of granular material.
  • 石川達也, 木次谷一平, 所哲也 地盤工学シンポジウム論文集 57th 159‐166 2012年11月22日 [査読無し][通常論文]
  • Seiichi Miura, Tatsuya Ishikawa Advances in Transportation Geotechnics II - Proceedings of the 2nd International Conference on Transportation Geotechnics, ICTG 2012 2012年10月19日 [査読無し][通常論文]
  • T. Ishikawa, S. Kawabata, S. Kameyama, R. Abe, T. Ono Advances in Transportation Geotechnics II - Proceedings of the 2nd International Conference on Transportation Geotechnics, ICTG 2012 118 -124 2012年10月19日 [査読無し][通常論文]
     
    This paper examines the effects of freezing and thawing on the mechanical behavior of granular base under unsaturated conditions through the long-term field measurement and FWD tests for pavement structure subjected to freeze-thaw actions, and by performing CBR tests for freeze-thawed base course material using a newly developed test apparatus. We also evaluate the influences of the change in the bearing capacity of granular base due to freeze-thawing on the fatigue life of pavement structures by applying the theoretical design method for pavement structures in consideration of the effects found in the above-mentioned experiments. As the results, it was revealed that the bearing capacity of granular base increases in freezing season and decreases due to increment of the water content in thawing season. This indicates that the freeze-thaw of granular base has a strong influence on the fatigue life of pavement structure in cold regions. © 2012 Taylor & Francis Group.
  • 所哲也, 石川達也, 中村努, 白井翔也 土木学会年次学術講演会講演概要集(CD-ROM) 67th ROMBUNNO.III-008 2012年08月01日 [査読無し][通常論文]
  • 村山巧, 川端伸一郎, 石川達也, 亀山修一, 小野丘 土木学会年次学術講演会講演概要集(CD-ROM) 67th ROMBUNNO.III-126 2012年08月01日 [査読無し][通常論文]
  • 吉田有喜, 石川達也 地盤工学研究発表会発表講演集(CD-ROM) 47th ROMBUNNO.726 2012年 [査読無し][通常論文]
  • 瀬川宙郷, 石川達也, 三浦清一, 所哲也 地盤工学会北海道支部技術報告集 (52) 27 -34 2012年01月 [査読無し][通常論文]
  • 吉田有喜, 石川達也, 三浦清一 地盤工学会北海道支部技術報告集 (52) 35 -42 2012年01月 [査読無し][通常論文]
  • T. Ishikawa, Y. Zhang, H. Segawa, S. Miura, T. Tokoro ADVANCES IN TRANSPORTATION GEOTECHNICS II 534 -540 2012年 [査読無し][通常論文]
     
    This paper proposes a testing method for evaluating the effect of water content on the deformation-strength characteristics of unsaturated base course materials. A medium-size triaxial apparatus for unsaturated soils was newly developed in order to examine the mechanical behavior of unsaturated base course materials subjected to fluctuation in water content and to shorten the testing time. It adopts the pressure membrane method with hydrophilic microporous membrane filters instead of the pressure plate method with ceramic disks, and controls both pore air pressure and pore water pressure at cap and pedestal separately. Results show that the proposed testing method carried out on this apparatus conform well to the results of previous researches. This indicates that the medium-size triaxial apparatus is highly useful at triaxial compression tests and water retention tests of unsaturated granular base course materials and in shorten the total testing time.
  • A. Inam, T. Ishikawa, S. Miura ADVANCES IN TRANSPORTATION GEOTECHNICS II 213 -218 2012年 [査読無し][通常論文]
     
    This research paper proposes a testing method to determine cyclic plastic deformation characteristics of unsaturated recycled crusher-run material, and accordingly examines the effect of moisture content under single-point loading and moving-wheel loading. In Japan, natural crusher-run material is employed in pavements for base course layer. Nowadays, in order to economize the cost of pavements, recycled crusher-run material made from construction waste is also used as base course material for low volume roads. A series of laboratory element test using multi-ring shear apparatus were carried out on recycled crusher-run material under different degrees of saturation. The experimental results show that, moisture content has obvious effect on cyclic plastic deformation of recycled crusher-run material. It is also explained that cyclic plastic deformation significantly increases under moving-wheel loading tests. Moreover, cyclic plastic deformation of recycled crusher-run material increases to some extent when compared with natural crusher-run material under same experimental conditions.
  • T. Ishikawa, S. Miura, K. Itou Unsaturated Soils - Proceedings of the 5th International Conference on Unsaturated Soils 1 549 -554 2011年12月01日 [査読無し][通常論文]
     
    This paper examines the effect of freeze-thaw action on the deformation-strength characteristics of crushable volcanic coarse-grained soil in unsaturated condition. An unsaturated triaxial apparatus, which can simulate freeze-thaw sequence in real foundations, was developed and a series of monotonic triaxial compression tests for a crushable volcanic coarse-grained soil exposed to freeze-thaw action were performed under various degrees of saturation. Test results showed that the freeze-thaw action made the amount of particle breakage under consolidation and shear increase for crushable volcanic coarse-grained soils, and its shear strength and deformation modulus under unsaturated conditions decreased by being exposed to freeze-thaw action. These indicate that the freeze-thaw action has strong influences on the deformation-strength characteristics of a crushable volcanic soil in unsaturated conditions even if the soil lacks in frost heave characteristics. © 2011 Taylor & Francis Group, London.
  • 石川 達也 地盤工学会誌 59 (12) 2011年12月01日 [査読無し][通常論文]
  • Tatsuya Ishikawa, Seiichi Miura Soils and Foundations 51 (5) 785 -799 2011年10月 [査読無し][通常論文]
     
    The objective of this study is to evaluate the effect of freeze-thaw action on the deformation-strength characteristics of crushable volcanic coarse-grained soils, wherein significant particle breakage occurs even under relatively low stress levels and saturated conditions. A series of monotonic triaxial compression tests was performed for volcanic coarsegrained soils under various freeze-thaw histories. On the basis of the test results, we examined the above-mentioned effect and the relationship between the degree of particle breakage and the freeze-thaw history. The results indicate that the degree of particle breakage under consolidation and shear increased with freeze-thaw action and consequently, the strength and the stiffness of the soils decreased with an increase in the number of freeze-thaw cycles. Moreover, to examine the influence of freeze-thaw action on the single-particle hardness of volcanic coarse-grained soils, single-particle crushing tests were conducted. The test results revealed that volcanic soil particles become more fragile after being exposed to freeze-thaw action, and as a result, the degree of particle breakage increases. These results indicate that the freeze-thaw action has a strong influence on the deformation-strength characteristics of crushable volcanic soils in terms of an increase in particle breakage, even if the soils lack frost-heave characteristics.
  • 村山巧, 川端伸一郎, 小野丘, 石川達也 土木学会年次学術講演会講演概要集(CD-ROM) 66th ROMBUNNO.III-404 2011年08月05日 [査読無し][通常論文]
  • INAM Aasim, ISHIKAWA Tatsuya, MIURA Seiichi, SEGAWA Hirosato 地盤工学会北海道支部技術報告集 (51) 95 -101 2011年02月 [査読無し][通常論文]
  • 山本隼央, 石川達也, 所哲也, 中村大, 山下聡 地盤工学研究発表会発表講演集(CD-ROM) 46th ROMBUNNO.515 2011年 [査読無し][通常論文]
  • Alexander Camarena Capriles, Tatsuya Ishikawa, Seiichi Miura GEOMECHANICS AND GEOTECHNICS: FROM MICRO TO MACRO, VOLS 1 AND 2 1 689 -693 2011年 [査読無し][通常論文]
     
    Failures due to rainfall, in slopes formed from volcanic soils are frequent in Hokkaido, Japan. In this study an analytical procedure to simulate rainfall-induced slope failure is proposed. The slope failure is simulated by combining two different methods, namely discontinuous analysis based on Distinct Element Method (DEM), and seepage analysis based on Finite Element Method (FEM). In order to simulate and analyze the behavior of the soil due to changes in water content accurately, the Contact-Bond model approach is used in the discontinuous simulations. To begin with, discontinuous analysis was performed for triaxial compression tests of saturated and unsaturated soils, and seepage analysis was also performed, in order to determine appropriate input parameters for the DEM simulations. The results obtained from the two numerical simulations were combined in a DEM model of the slope where the failure dynamics were examined. With this method, the efficacy of using the Contact-Bond model approach for the failure dynamics can be analyzed. The validity of this analytical procedure was evaluated by comparing experimental results of test models with the numerical simulation.
  • 石川 達也 地盤工学会誌 58 (10) 28 -29 2010年10月01日 [査読無し][通常論文]
     
    The JGS Hokkaido Branch has continuously and energetically supported geotechnical engineers in Hokkaido since its establishment. The support activities are conducted through the holding of some annual academic events such as technical report conferences and geotechnical seminars, international activities such as international conferences and symposiums, and committee activities of various technical committees established by the branch. This paper introduces a part of the support activities that the JGS Hokkaido Branch has grappled with so far and their achievements in order to support many ...
  • 川村志麻, 五十嵐はるか, 三浦清一, 石川達也, 横浜勝司 土木学会年次学術講演会講演概要集(CD-ROM) 65th ROMBUNNO.III-046 2010年08月05日 [査読無し][通常論文]
  • 石川達也, 本間裕助, 山下聡, 所哲也 地盤工学研究発表会発表講演集 45th (1) 875 -876 2010年07月15日 [査読無し][通常論文]
  • 関根悦夫, 石川達也 日本鉄道施設協会誌 48 (2) 140 -143 2010年02月01日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也 日本鉄道施設協会誌 48 (2) 140 -143 2010年02月 [査読無し][通常論文]
  • 石川達也, 里優, 赤川敏, 川村志麻 地盤工学会北海道支部技術報告集 (50) 163 -172 2010年01月 [査読無し][通常論文]
  • 石川達也, 鰐渕博, 阿部圭市, 岡田芳和 脳卒中 32 (2) 185-189 (J-STAGE) 2010年 [査読無し][通常論文]
  • Tetsuya Tokoro, Tatsuya Ishikawa, Seiichi Miura UNSATURATED SOILS: EXPERIMENTAL STUDIES IN UNSATURATED SOILS AND EXPANSIVE SOILS 179 -184 2010年 [査読無し][通常論文]
     
    Many steady-state methods for measurement of the permeability coefficient have been proposed. However, an extensive amount of time is required to complete a series of permeability tests. The purpose of this paper is to shorten the testing time of the steady-state pressure method by using a membrane filter. In order to measure the unsaturated permeability, a triaxial apparatus capable of performing the steady-state membrane method was developed. The permeability test was conducted by applying matric suction and a differential water head to both ends of the specimen at the same time. A water retention test can be simultaneously conducted by measuring inflow and outflow of water. As a result, soil-water characteristic curves and relationships between degree of saturation and permeability coefficient were in good agreement with previously published experimental. data. The newly developed pressure membrane method takes a shorter time than the pressure plate method.
  • T. Ishikawa, K. Ito, S. Miura UNSATURATED SOILS: EXPERIMENTAL STUDIES IN UNSATURATED SOILS AND EXPANSIVE SOILS 159 -164 2010年 [査読無し][通常論文]
     
    The objective of this study is to evaluate the effect of freeze-thaw action on the soil water characteristics of crushable granular materials. An unsaturated triaxial apparatus, which could apply freeze-thaw sequence to a test specimen, was newly developed, and a series of water retention tests for a crushable volcanic coarse-grained soil and non-crushable sand exposed to various freeze-thaw histories were performed. The change in the shape of water retention curves due to freeze-thawing and the relationship between degree of particle breakage and freeze-thaw history are examined. Results revealed that since particle breakage for crushable volcanic coarse-grained soil increased with an increase in freeze-thawing cycles, the freeze-thaw action has strong influences on the soil water characteristics even if the soil lacks in frost heave characteristics.
  • 斜面の凍上被害と対策のガイドライン
    地盤工学会北海道支部 2010年 [査読無し][通常論文]
  • 亀井威彦, 石川達也, 関根悦夫, 三浦清一 鉄道技術連合シンポジウム講演論文集 16th 221 -222 2009年12月02日 [査読無し][通常論文]
  • 亀井 威彦, 石川 達也, 関根 悦夫, 三浦 清一 鉄道技術連合シンポジウム(J-Rail)講演論文集 2009 (16) 221 -222 2009年12月02日 [査読無し][通常論文]
     
    This paper presents a simple cyclic plastic deformation analysis of ballasted track subjected to cyclic loads in terms of the strength and deformation of railroad ballast. A new analytical procedure with linear elastic FEM considering the cumulative strain derived from cyclic triaxial compression test results of railroad ballast was proposed. By comparing real-scale model test of ballasted track with the analytical results, and it was revealed that the analytical procedure could roughly estimate the residual settlement of railroad ballast under cyclic loads.
  • T. Ishikawa, S. Miura, S. Akagawa, M. Sato, S. Kawamura Prediction and Simulation Methods for Geohazard Mitigation - Proceedings of the International Symposium on Prediction and Simulation Methods for Geohazard Mitigation, IS-KYOTO 2009 409 -415 2009年12月01日 [査読無し][通常論文]
     
    This paper presents a new analytical procedure with a coupled thermo-mechanical FE analysis to simulate the mechanical behavior of frost heaved soil slope during freezing and thawing. First, a coupled thermo-mechanical FE analysis, which can consider the change in deformation-strength characteristics due to freeze-thaw action, was newly developed. Next, to examine the applicability of the coupled analysis and to analyze the mechanical behavior of frost heaved soil slopes during freezing and thawing, a numerical simulation of a freeze-thawing test for model slope was conducted. As the results, it is revealed that the coupled analysis proposed in this paper is an effective method to simulate the slope behavior during freezing and thawing, and that freeze-thaw action has a profound influence on the slope failure at a subsurface layer in cold regions. © 2009 Taylor & Francis Group.
  • T. Ishikawa, T. Kamei, E. Sekine, Y. Ohnishi Bearing Capacity of Roads, Railways and Airfields - Proceedings of the 8th International Conference on the Bearing Capacity of Roads, Railways and Airfields 2 1207 -1218 2009年12月01日 [査読無し][通常論文]
     
    The paper proposes a new analytical procedure that involves discontinuous analysis to estimate the bearing capacity of granular roadbed used in ballasted track, namely "railroad ballast." To examine the applicability of the procedure, a series of numerical simulation bearing capacity tests for a 1/5 scale model of a real ballasted track were performed by employing discontinuous deformation analysis (DDA) that regards a particle of crushed stone as an irregular polygon. By comparing the analytical results and experimental results, the effect of roadbed stiffness on the bearing capacity of railroad ballast was examined. As the result, it was revealed that the roadbed stiffness has significant influence on the bearing capacity of railroad ballast, and that discontinuous analysis is an effective method to simulate the mechanical behavior of railroad ballast if the roadbed, which has been often modeled as a continuum, can be approximated with discontinuous modeling well. © 2009 Taylor & Francis Group, London.
  • S. Kawamura, S. Miura, T. Ishikawa, H. Ino Prediction and Simulation Methods for Geohazard Mitigation - Proceedings of the International Symposium on Prediction and Simulation Methods for Geohazard Mitigation, IS-KYOTO 2009 25 -31 2009年12月01日 [査読無し][通常論文]
     
    Collapse of slope formed from volcanic soils has been frequently caused in Hokkaido, Japan. This study aims at clarifying failure mechanism of volcanic slope caused by both rainfall and freeze-thaw action. In particular, the effects of freeze-thaw action, slope angle, density and friction of impermeable layer in the slope on mechanical behavior at failure were detailedly investigated on volcanic slopes having several shapes. © 2009 Taylor & Francis Group.
  • 関根悦夫, 石川達也 鉄道総研報告 23 (10) 17 -22 2009年10月01日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也 鉄道総研報告 23 (10) 17 -22 2009年10月 [査読無し][通常論文]
  • 石川達也, 里優, 赤川敏, 三浦清一 土木学会年次学術講演会講演概要集(CD-ROM) 64th (Disk 1) ROMBUNNO.III-128 2009年08月03日 [査読無し][通常論文]
  • 石川達也, 福島宏文, 遠藤秀博, 今泉浩明 地盤工学研究発表会発表講演集 44th 183 -184 2009年07月13日 [査読無し][通常論文]
  • 石川達也, 所哲也, 伊藤康平, 三浦清一 地盤工学研究発表会発表講演集 44th 685 -686 2009年07月13日 [査読無し][通常論文]
  • 川村志麻, 中野博貴, 三浦清一, 石川達也 地盤工学研究発表会発表講演集 44th 687 -688 2009年07月13日 [査読無し][通常論文]
  • 所哲也, 石川達也, 三浦清一 地盤工学研究発表会発表講演集 44th 963 -964 2009年07月13日 [査読無し][通常論文]
  • 大塚寿貴, 石川達也, 三浦清一 地盤工学研究発表会発表講演集 44th 877 -878 2009年07月13日 [査読無し][通常論文]
  • 不飽和土研究会, 石川 達也 地盤工学会誌 57 (4) 2009年04月01日 [査読無し][通常論文]
  • 関根悦夫, 桃谷尚嗣, 石川達也 地盤工学会誌 57 (3) 54-61,1(1) 2009年03月01日 [査読無し][通常論文]
  • 関根 悦夫, 桃谷 尚嗣, 石川 達也 地盤工学会誌 57 (3) 54 -61 2009年03月01日 [査読無し][通常論文]
  • 所哲也, 石川達也, 三浦清一 地盤工学会北海道支部技術報告集 (49) 249 -252 2009年01月 [査読無し][通常論文]
  • 伊藤康平, 石川達也, 三浦清一 地盤工学会北海道支部技術報告集 (49) 245 -248 2009年01月 [査読無し][通常論文]
  • 川村志麻, 中野博貴, 三浦清一, 石川達也 地盤工学会北海道支部技術報告集 (49) 233 -240 2009年01月 [査読無し][通常論文]
  • T. Ishikawa, S. Miura, T. Tokoro Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: The Academia and Practice of Geotechnical Engineering 1 833 -836 2009年 [査読無し][通常論文]
     
    This paper proposes new testing methods for evaluating the effects of freeze-thaw action on the deformation-strength characteristics and water retention-permeability characteristics of granular materials in unsaturated conditions. A triaxial and a permeability apparatus, which have a cooling system to control the temperature of the soil specimen, were developed in order to examine the hydro-mechanical behavior of unsaturated soils subjected to freeze-thaw sequence similar to that experienced by in-site soil in cold regions. Results indicate that the proposed testing methods with the newly developed test apparatuses are highly useful in the evaluation of the effects of the freeze-thaw action on the hydro-mechanical behavior of unsaturated soils. © 2009 IOS Press.
  • S. Kawamura, S. Miura, T. Ishikawa, H. Ino Prediction and Simulation Methods for Geohazard Mitigation 25 -31 2009年01月01日 [査読無し][通常論文]
     
    © 2009 Taylor & Francis Group, London. Collapse of slope formed from volcanic soils has been frequently caused in Hokkaido, Japan. This study aims at clarifying failure mechanism of volcanic slope caused by both rainfall and freeze-thaw action. In particular, the effects of freeze-thaw action, slope angle, density and friction of impermeable layer in the slope on mechanical behavior at failure were detailedly investigated on volcanic slopes having several shapes.
  • T. Ishikawa, S. Miura, S. Akagawa, M. Sato, S. Kawamura Prediction and Simulation Methods for Geohazard Mitigation 409 -416 2009年01月01日 [査読無し][通常論文]
     
    © 2009 Taylor & Francis Group, London. This paper presents a new analytical procedure with a coupled thermo-mechanical FE analysis to simulate the mechanical behavior of frost heaved soil slope during freezing and thawing. First, a coupled thermo-mechanical FE analysis, which can consider the change in deformation-strength characteristics due to freeze-thaw action, was newly developed. Next, to examine the applicability of the coupled analysis and to analyze the mechanical behavior of frost heaved soil slopes during freezing and thawing, a numerical simulation of a freeze-thawing test for model slope was conducted. As the results, it is revealed that the coupled analysis proposed in this paper is an effective method to simulate the slope behavior during freezing and thawing, and that freeze-thaw action has a profound influence on the slope failure at a subsurface layer in cold regions.
  • T. Ishikawa, S. Miura 12th International Conference on Computer Methods and Advances in Geomechanics 2008 2 1219 -1226 2008年12月01日 [査読無し][通常論文]
     
    This paper proposes a new analytical procedure to simulate the frost heave of granular materials. The objective of the research is to examine the applicability of discontinuous analysis to numerical simulation for the mechanical behaviour of granular materials subjected to freeze-thaw action. In this paper, numerical simulations of freeze-thawing triaxial compression tests for glass beads were performed with three-dimensional DEM coupled with a thermal analysis, and the applicability of the DEM to the freezing-thawing behaviour of granular materials was discussed. As the results, it was shown that the proposed DEM model that puts many small elements between soil particles, which expand with dropping the temperature, can simulate the freezingthawing behaviour of granular materials to some extent though there is room for further investigation as to numerical modelling and setting analytical parameters.
  • 石川 達也 地盤工学会誌 56 (12) 2008年12月01日 [査読無し][通常論文]
  • 石川達也, 里優, 三浦清一, 赤川敏, 川村志麻 岩の力学国内シンポジウム講演論文集 12th(CD-ROM) ROMBUNNO.98 2008年09月01日 [査読無し][通常論文]
  • 石川 達也, 三浦 清一, 川村 志麻 土木学会年次学術講演会講演概要集 63 (3) 141 -142 2008年09月 [査読無し][通常論文]
  • 川村 志麻, 井野 寿人, 三浦 清一, 石川 達也, 中野 博貴 土木学会年次学術講演会講演概要集 63 (3) 191 -192 2008年09月 [査読無し][通常論文]
  • 亀井威彦, 石川達也, 佐々博明 土木学会年次学術講演会講演概要集(CD-ROM) 63rd (Disk 2) ROMBUNNO.4-021 2008年08月13日 [査読無し][通常論文]
  • 川村志麻, 井野寿人, 三浦清一, 石川達也, 中野博貴 土木学会年次学術講演会講演概要集(CD-ROM) 63rd (Disk 1) ROMBUNNO.3-096 2008年08月13日 [査読無し][通常論文]
  • 石川達也, 三浦清一, 川村志麻 土木学会年次学術講演会講演概要集(CD-ROM) 63rd (Disk 1) ROMBUNNO.3-071 2008年08月13日 [査読無し][通常論文]
  • 関根悦夫, 石川達也 鉄道総研報告 22 (8) 11 -16 2008年08月01日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也 鉄道総研報告 22 (8) 11 -16 2008年08月 [査読無し][通常論文]
  • 川村志麻, 井野寿人, 三浦清一, 石川達也 地盤工学研究発表会発表講演集 43rd 2043 -2044 2008年06月12日 [査読無し][通常論文]
  • 吉田永, 三浦清一, 石川達也 地盤工学研究発表会発表講演集 43rd 767 -768 2008年06月12日 [査読無し][通常論文]
  • 井野寿人, 川村志麻, 三浦清一, 石川達也 地盤工学会北海道支部技術報告集 (48) 97 -106 2008年02月 [査読無し][通常論文]
  • 細田充, 石川達也, 三浦清一 地盤工学会北海道支部技術報告集 (48) 253 -262 2008年02月 [査読無し][通常論文]
  • T. Ishikawa, M. Hosoda, S. Miura, E. Sekine ADVANCES IN TRANSPORTATION GEOTECHNICS 185 -191 2008年 [査読無し][通常論文]
     
    This paper presents an experimental study to evaluate the effects of water content on the mechanical behavior of gravel subjected to moving wheel loads. First, two types of small scale model tests which adopted a fixed-place loading method and a moving loading method were performed with a base course material under air-dried condition and saturated condition. Next, two types of multi-ring shear tests which could consider a change in direction of principal stresses like traffic loads were performed likewise. Based on test results, the relationships between the water content of test samples and the deformation-strength characteristics were examined. As the results, it was revealed that the shear strength of gravel decreased and the cumulative residual strain increased due to the saturation in both tests, regardless of loading methods. This indicates that the water content of gravel influences the mechanical behavior of granular roadbed strongly.
  • 石川 達也 日本鉄道施設協会誌 45 (11) 933 -935 2007年11月 [査読無し][通常論文]
  • 井野寿人, 川村志麻, 木幡行宏, 三浦清一, 石川達也, 横浜勝司 土木学会年次学術講演会講演概要集(CD-ROM) 62nd (Disk 1) ROMBUNNO.3-007 -14 2007年09月01日 [査読無し][通常論文]
  • 石川達也, 三浦清一, 横浜勝司, 川村志麻 土木学会年次学術講演会講演概要集(CD-ROM) 62nd (Disk 1) ROMBUNNO.3-014 -28 2007年09月01日 [査読無し][通常論文]
  • 石川 達也, 関根 悦夫, 三和 雅史 応用力学論文集 10 513 -522 2007年08月29日 [査読無し][通常論文]
  • 尾崎悠太, 石川達也, 三浦清一 地盤工学研究発表会発表講演集 42nd 743 -744 2007年06月11日 [査読無し][通常論文]
  • 石川達也, 福津圭基, 三浦清一, 関根悦夫 地盤工学研究発表会発表講演集 42nd 995 -996 2007年06月11日 [査読無し][通常論文]
  • 伊藤康平, 三浦清一, 石川達也, 尾崎悠太 地盤工学研究発表会発表講演集 42nd 745 -746 2007年06月11日 [査読無し][通常論文]
  • 粒子形状の評価と土の力学挙動
    松島亘志, 前田健一, 石川達也 土と基礎 55 (6) 37 -44 2007年06月01日 [査読無し][通常論文]
  • 松島亘志, 前田健一, 石川達也 土と基礎 55 (6) 37-44,1(4) 2007年06月01日 [査読無し][通常論文]
  • 関根悦夫, 石川達也 鉄道総研報告 21 (6) 17 -22 2007年06月01日 [査読無し][通常論文]
  • 松島 亘志, 前田 健一, 石川 達也 土と基礎 55 (6) 37 -44 2007年06月01日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也 鉄道総研報告 21 (6) 17 -22 2007年06月 [査読無し][通常論文]
  • 石川達也, 兵動正幸, 陳光斉 土と基礎 55 (5) 47 -52 2007年05月01日 [査読無し][通常論文]
  • 石川 達也, 兵動 正幸, 陳 光斉 土と基礎 55 (5) 47 -52 2007年05月01日 [査読無し][通常論文]
  • 片桐雅明, 安福規之, 藤山哲雄, 石川達也 土と基礎 55 (4) 62-68,1(4) 2007年04月01日 [査読無し][通常論文]
  • 片桐 雅明, 安福 規之, 藤山 哲雄, 石川 達也 土と基礎 55 (4) 62 -68 2007年04月01日 [査読無し][通常論文]
  • 石川 達也, 関根 悦夫, 三浦 清一 理論応用力学講演会 講演論文集 56 (0) 93 -93 2007年03月07日 [査読無し][通常論文]
     
    本研究は,繰返し荷重作用時のバラスト軌道の変形特性を解明し,鉄道線路施設の効率的な維持管理を行うために,道床バラストの材料特性を考慮したバラスト軌道の挙動解析法について検討した。その結果,道床バラストの累積ひずみ特性を考慮したFEM解析による道床部の繰返し塑性変形量の簡易推定方法を提案した。また,模型試験結果との比較検討から,提案した推定法の妥当性を検証し,累積損傷度理論を応用した場合,簡易な線形弾性解析でも道床の弾塑性挙動をある程度推定できることを示した。
  • 福津圭基, 石川達也, 三浦清一, 関根悦夫 地盤工学会北海道支部技術報告集 (47) 155 -160 2007年02月 [査読無し][通常論文]
  • 玉置和美, 石川達也, 三浦清一 土木学会年次学術講演会講演概要集(CD-ROM) 61st (Disk 1) ROMBUNNO.3-355 2006年09月01日 [査読無し][通常論文]
  • 石川達也, 細田充, 関根悦夫, 三浦清一 地盤工学研究発表会発表講演集 41st 1071 -1072 2006年06月20日 [査読無し][通常論文]
  • 尾崎悠太, 三浦清一, 石川達也, 熊谷浩輔 地盤工学研究発表会発表講演集 41st 873 -874 2006年06月20日 [査読無し][通常論文]
  • 関根悦夫, 石川達也 鉄道総研報告 20 (4) 17 -22 2006年04月10日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也 鉄道総研報告 20 (4) 17 -22 2006年04月 [査読無し][通常論文]
  • 杉山圭大, 石川達也, 三浦清一, 関根悦夫 地盤工学会北海道支部技術報告集 (46) 175 -184 2006年02月 [査読無し][通常論文]
  • 石川達也 地盤工学会北海道支部技術報告集 (46) 185 -194 2006年02月 [査読無し][通常論文]
  • 小林慶祐, 石川達也, 関根悦夫, 三浦清一 地盤工学会北海道支部技術報告集 (46) 167 -174 2006年02月 [査読無し][通常論文]
  • 山木正彦, 所哲也, 三浦清一, 石川達也, 横浜勝司 地盤工学会北海道支部技術報告集 (46) 215 -220 2006年02月 [査読無し][通常論文]
  • 石川 達也, 玉置 和美, 三浦 清一 応用力学論文集 9 641 -648 2006年 [査読無し][通常論文]
     
    This paper presentsa numerical experiment to reveal the effect of freeze-thaw action on the mechanical behavior of granular materials in tams of micmmechanics. The odjective is to propose a new analytical procedure to simulate the mechanical behavior of granular materials subjected to freeze-thaw sequence. Numerical simulations of freezing-thawing triaxial compression tests were performed with 3D DEM coupled with a thermal analysis, and the applicability of the DEM to the freezing-thawing behavior of granular materials was discussed As the results, it was showed that the proposed DEM model that puts many small elements which expand with dropping the temperature between soil particles can simulate the freezing-thawing behavior of granular materials to some extent though there is room for further investigation as to numerical modeling and setting analytical parameters.
  • T. Ishikawa, K. Kobayashi, E. Sekine, Y. Ohnishi Geomechanics and Geotechnics of Particulate Media 389 -395 2006年 [査読無し][通常論文]
     
    This paper examines the effects of particle shape on the bearing capacity of railroad ballast in numerical simulations with discontinuous analysis. A series of numerical simulations that regard a ballast particle as a regular or an irregular polygon were performed. Here, the particle shape of railroad ballast in numerical models was evaluated by two kinds of analytical methods, namely "argument function" and "radius function." Next, the correlations of the evaluation indexes of particle shape with the strength-deformation characteristics of granular materials in numerical models were examined. As the result, it can be observed that the particle shape of numerical models, especially the angularity has greater effect on the bearing capacity of railroad ballast than the sphericity, and that the imitation of the shape of real ballast particles makes analytical results similar to experimental results.
  • T. Ishikawa, S. Miura, S. Yokohama, R. G. Mijares Geomechanics and Geotechnics of Particulate Media 121 -126 2006年 [査読無し][通常論文]
     
    The objective of this study is to evaluate the effect of degree of saturation on the strength characteristics of volcanic coarse-grained soils, wherein particle breakage significantly takes place during loading and deformation processes, under various degrees of saturation conditions. In this paper, a series of monotonic triaxial compression tests for two kinds of volcanic coarse-grained soils are performed under various degrees of saturation conditions, and the relationships between degree of saturation, degree of particle breakage and strength are examined based on experimental results. As the result, the following conclusions are obtained: The shear strength of crushable coarse-grained volcanic soils decreases with an increase in the amount of particle breakage. Particle breakage is strongly influenced by the degree of saturation of the soil matrix. Accordingly, as the crushable volcanic coarse-grained soil becomes saturated, particle breakage becomes more dominant, thereby decreasing the shear strength of the soil.
  • 三浦 清一, 石川 達也 土と基礎 53 (12) 39 -40 2005年12月01日 [査読無し][通常論文]
  • 三浦清一, 八木一善, 石川達也 土と基礎 53 (10) 39-46,1(1)-1(3) 2005年10月01日 [査読無し][通常論文]
  • 三浦 清一, 八木 一善, 石川 達也 土と基礎 53 (10) 39 -46 2005年10月01日 [査読無し][通常論文]
  • 小林慶祐, 石川達也, 三浦清一, 関根悦夫 地盤工学研究発表会発表講演集 40th 909 -910 2005年06月15日 [査読無し][通常論文]
  • 杉山圭大, 石川達也, 三浦清一, 関根悦夫 地盤工学研究発表会発表講演集 40th 545 -546 2005年06月15日 [査読無し][通常論文]
  • 関根悦夫, 河野昭子, 村本勝己, 石川達也 地盤工学研究発表会発表講演集 40th 1169 -1170 2005年06月15日 [査読無し][通常論文]
  • 横浜勝司, 三浦清一, 石川達也 地盤工学研究発表会発表講演集 40th 2165 -2166 2005年06月15日 [査読無し][通常論文]
  • 関根悦夫, 石川達也, 河野昭子 鉄道総研報告 19 (2) 17 -22 2005年02月03日 [査読無し][通常論文]
  • 関根悦夫, 石川達也 鉄道総研報告 19 (2) 23 -28 2005年02月03日 [査読無し][通常論文]
  • 泉剛生, 石川達也, 関根悦夫, 室野剛隆 地盤工学会北海道支部技術報告集 (45) 145 -152 2005年02月 [査読無し][通常論文]
  • 玉置和美, 石川達也, 三浦清一 地盤工学会北海道支部技術報告集 (45) 219 -224 2005年02月 [査読無し][通常論文]
  • 石川達也, 関根悦夫, 杉山圭大, 三浦清一 地盤工学会北海道支部技術報告集 (45) 105 -114 2005年02月 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也, 河野 昭子 鉄道総研報告 19 (2) 17 -22 2005年02月 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也 鉄道総研報告 19 (2) 23 -28 2005年02月 [査読無し][通常論文]
  • 石川達也, 堀田大介, 三浦清一, 柏谷匡胤 土木学会年次学術講演会講演概要集(CD-ROM) 59th (Disk 1) 3 -011 2004年09月01日 [査読無し][通常論文]
  • 堀田大介, 三浦清一, 石川達也 土木学会年次学術講演会講演概要集(CD-ROM) 59th (Disk 1) 3 -012 2004年09月01日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也, 河野 昭子 地盤工学研究発表会 発表講演集 39 (0) 1069 -1070 2004年06月15日 [査読無し][通常論文]
     
    バラストと呼ばれる粒状材料,まくらぎ,レールから構成されるバラスト軌道は,列車の繰返し荷重によりバラスト部分に塑性変形が生じ,軌道の変形が基準値を超過した場合には補修を行っている。このため,効率的な軌道の維持管理を行うには,バラスト部分の変形特性を解明する必要がある。そこで,バラストの厚さが繰返し荷重による塑性変形に及ぼす影響を検討するため,車輪走行による軌道模型繰返し載荷試験等を行った。その結果,バラスト厚さの増加とともに塑性変形の進行速度は増加する傾向にあるが,進行速度にピークを迎える道床厚さがあることが示唆された。
  • 河野 昭子, 石川 達也, 関根 悦夫, 室野 剛隆, 泉 剛生 地盤工学研究発表会 発表講演集 39 (0) 1769 -1770 2004年06月15日 [査読無し][通常論文]
     
    本報告では、L2地震動に対応した省力化軌道の耐震性能評価法の研究開発の一環として、平面ひずみ状態を仮定した模型省力化軌道(実軌道の横断面を模擬)の振動台試験を行い、CA注入層が水平加振時の動的応答特性に及ぼす影響について検討した。まず、模型バラスト軌道の振動台試験結果との比較検討により、CA注入層の有無により模型軌道の動的応答特性に差異が生じることを明かにした。次に、応答加速度と応答変位の観点から、CA注入層の設置条件の差異が模型省力化軌道の耐震性能に及ぼす影響を検討した。この結果、省力化軌道構造の耐震性能の向上には、道床表面の鋪装化とCA注入層厚の増加が効果的であることを明らかにした。
  • 石川 達也, 堀田 大介, 柏谷 匡胤, 三浦 清一 地盤工学研究発表会 発表講演集 39 (0) 863 -864 2004年06月15日 [査読無し][通常論文]
     
    粗粒材料の要素試験においては、寸法効果(供試体寸法に対する最大粒径)やメンブレンペネトレーションの影響のため、試験機の大型化や様々な補正手法が提案されてきた。しかし、汎用性、利便性の観点から、簡素な構成で精度良い試験結果が得られる試験機の開発が望まれている。本研究では、粗粒材料を対象とした単純せん断試験機として"多段式リングせん断試験機"を試作した。本試験機は剛なリングによって側方拘束するためメンブレンペネトレーションの影響が無く、容易に単純せん断変形を生じさせることができる。破砕性土を含む粗粒材料や豊浦砂に対する一連の試験から、試作した試験機の性能評価および結果の適用について考察を試みた。
  • 関根悦夫, 石川達也, 木幡行宏 鉄道総研報告 18 (3) 17 -22 2004年03月05日 [査読無し][通常論文]
  • 関根 悦夫, 石川 達也, 木幡 行宏 鉄道総研報告 18 (3) 17 -22 2004年03月 [査読無し][通常論文]
  • 石川達也, 関根悦夫, 河野昭子, 小林慶祐 地盤工学会北海道支部技術報告集 (44) 321 -330 2004年02月 [査読無し][通常論文]
  • 堀田大介, 三浦清一, 石川達也 地盤工学会北海道支部技術報告集 (44) 253 -258 2004年02月 [査読無し][通常論文]
  • 三浦清一, 石川達也, 横浜勝司 土と基礎 51 (12) 77-81,1(1)-1(6) 2003年12月01日 [査読無し][通常論文]
  • 三浦 清一, 石川 達也, 横濱 勝司 土と基礎 51 (12) 77 -81 2003年12月01日 [査読無し][通常論文]
  • 石川 達也, 関根 悦夫, 室野 剛隆 地盤工学研究発表会 発表講演集 38 (0) 1833 -1834 2003年06月06日 [査読無し][通常論文]
     
    本報告では、L2地震動に対応したバラスト軌道の耐震性能評価法の研究開発の一環として、平面ひずみ状態を仮定した模型バラスト軌道(実軌道の横断面を模擬)の振動台試験を行い、水平加振時の動的応答特性に対する2次元近似の妥当性について検討した。まず、模型まくらぎの幅、質量、設置本数等を変えて実施した振動台試験結果から、模型まくらぎの形状や質量の違いにより模型バラスト軌道の動的応答特性に差異が生じることを明かにした。次に、バラスト軌道に対する2次元地震時応答解析の適用方法を検討するため、単粒度砕石の動的応答特性と本試験結果を関係づけて考察し、3次元場における本試験結果の解釈方法を提案した。
  • 関根 悦夫, 榎本 秀明, 村本 勝己, 蒋 関魯, 石川 達也 地盤工学研究発表会 発表講演集 38 (0) 675 -676 2003年06月06日 [査読無し][通常論文]
     
    近年,土構造物に使用する良質な自然砕石の入手が,環境問題に関する規制もあり,非常に困難となりつつある。一方,ごみ処理問題の解決策として,ごみ焼却灰の溶融固化技術が着目され,その適用が検討されている。そこで,地球環境への負荷低減に寄与するため,ごみ焼却灰を溶融固化して作製した人工砕石を,土構造物に適用することを目的として,大型三軸試験により強度・変形特性の検討を行った。検討の結果,自然砕石に劣らない強度・変形特性を有していることが確認された。なお,用いた人工砕石は,溶融固化したごみ焼却灰がガラス質とならないよう温度管理して作製したものである。
  • 関根悦夫, 桃谷尚嗣, 石川達也 舗装 38 (5) 17 -22 2003年05月01日 [査読無し][通常論文]
  • 三和雅史, 河西智司, 石川達也, 奥村陽一, 東川恒也 鉄道総研報告 17 (2) 35 -40 2003年02月06日 [査読無し][通常論文]
  • 三和 雅史, 河西 智史, 石川 達也 鉄道総研報告 17 (2) 35 -40 2003年02月 [査読無し][通常論文]
  • 石川達也, 関根悦夫, 三浦清一, 中村貴久 地盤工学会北海道支部技術報告集 (43) 263 -272 2003年01月 [査読無し][通常論文]
  • 三和 雅史, 石川 達也, 奥村 陽一, 大山 達雄 日本オペレーションズ・リサーチ学会秋季研究発表会アブストラクト集 2002 114 -115 2002年09月11日 [査読無し][通常論文]
  • 石川達也, 堀池高広 鉄道総研報告 16 (4) 17 -22 2002年04月05日 [査読無し][通常論文]
  • 石川 達也, 堀池 高広 鉄道総研報告 16 (4) 17 -22 2002年04月 [査読無し][通常論文]
  • 石川 達也, 関根 悦夫, 村本 勝己, 室野 剛隆 地盤工学研究発表会 発表講演集 37 (0) 1819 -1820 2002年 [査読無し][通常論文]
  • 三和 雅史, 石川 達也, 大山 達雄 日本オペレーションズ・リサーチ学会春季研究発表会アブストラクト集 2001 86 -87 2001年05月01日 [査読無し][通常論文]
  • 三和雅史, 石川達也, 大山達雄 土木計画学研究・講演集 (22,Pt.1) 467 -470 1999年10月20日 [査読無し][通常論文]
  • 内田雅夫, 石川達也, 三和雅史 土木学会年次学術講演会講演概要集 第4部 53rd 918 -919 1998年10月 [査読無し][通常論文]
  • 石川達也 新線路 52 (9) 28 -30 1998年09月 [査読無し][通常論文]
  • 内田雅夫, 三和雅史, 石川達也 土木学会年次学術講演会講演概要集 第4部 52nd 700 -701 1997年09月 [査読無し][通常論文]
  • 内田雅夫, 石川達也, 三和雅史 日本鉄道施設協会誌 34 (2) 122 -125 1996年02月 [査読無し][通常論文]
  • 内田雅夫, 石川達也, 三和雅史 日本鉄道施設協会誌 34 (1) 27 -30 1996年01月 [査読無し][通常論文]
  • 石川達也 日本鉄道施設協会誌 33 (7) 484 -487 1995年07月 [査読無し][通常論文]
  • 石川達也 日本鉄道施設協会誌 33 (6) 427 -430 1995年06月 [査読無し][通常論文]
  • 石川達也, 大西有三 土質工学研究発表会発表講演集 30th (3-3) 2081 -2082 1995年05月 [査読無し][通常論文]
  • 石川 達也, 内田 雅夫 鉄道総研報告 9 (4) p31 -36 1995年04月 [査読無し][通常論文]
  • 内田雅夫, 石川達也, 名村明, 高井秀之, 三和雅史 鉄道総研報告 9 (4) 37 -42 1995年04月 [査読無し][通常論文]
  • 石川達也, 内田雅夫 鉄道総研報告 9 (4) 31 -36 1995年04月 [査読無し][通常論文]
  • 須長誠, 石川達也, 名村明 土と基礎 43 (2) 10 -14 1995年02月 [査読無し][通常論文]
  • 内田雅夫, 長戸正二, 高井秀之, 石川達也 日本機械学会交通・物流部門大会講演論文集 3rd (Tetsudo Shinpojiumuhen) 85 -90 1994年12月 [査読無し][通常論文]
  • 石川達也, 名村明, 堀池高広 鉄道総研報告 8 (11) 31 -36 1994年11月 [査読無し][通常論文]
  • 石川達也 日本鉄道施設協会誌 32 (8) 562 -565 1994年08月 [査読無し][通常論文]
  • 三浦重, 石川達也 日本鉄道施設協会誌 32 (7) 506 -509 1994年07月 [査読無し][通常論文]
  • 名村明, 石川達也 土質工学研究発表会発表講演集 29th (3-3) 2083 -2084 1994年05月 [査読無し][通常論文]
  • 石川達也, 名村明 土質工学研究発表会発表講演集 29th (3-3) 2085 -2086 1994年05月 [査読無し][通常論文]
  • 名村明, 石川達也, 堀池高広 日本鉄道施設協会誌 32 (1) 26 -29 1994年01月 [査読無し][通常論文]
  • 石川達也, 名村明 土質工学会シンポジウム発表論文集 (Ryujotai no Rikigaku...) 51 -52 1993年12月 [査読無し][通常論文]
  • 名村明, 石川達也, 三浦重, 内田雅夫, 堀池高広 鉄道総研報告 7 (10) 47 -54 1993年10月 [査読無し][通常論文]
  • 石川達也, 内田雅夫, 小倉英章 鉄道総研報告 7 (8) 33 -40 1993年08月 [査読無し][通常論文]
  • 石川達也, 小倉英章 日本鉄道施設協会誌 31 (8) 555 -558 1993年08月 [査読無し][通常論文]
  • 嘉門雅史, 青木一男, 石川達也 土木学会関西支部年次学術講演会講演概要 1987 III.21.1-III.21.2 1987年04月 [査読無し][通常論文]

共同研究・競争的資金等の研究課題

  • 表層凍結斜面崩壊メカニズムの地盤工学的解析に基づく東欧校倉木造教会堂保存の研究
    日本学術振興会:科学研究費助成事業 国際共同研究加速基金(国際共同研究強化(B))
    研究期間 : 2019年10月 -2023年03月 
    代表者 : 上北 恭史, 藤田 香織, マルティネス アレハンドロ, 石川 達也
  • 粗粒材の長期劣化を考慮した新たな交通施設の維持管理方法:経験知から科学知の保守へ
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2019年04月 -2023年03月 
    代表者 : 早野 公敏, 石川 達也, 桃谷 尚嗣, 中村 貴久
  • 高緯度寒冷地盤の雨慣れ度を考慮した気候変動下の豪雨災害リスク評価法の開発
    日本学術振興会:科学研究費助成事業 挑戦的研究(萌芽)
    研究期間 : 2018年06月 -2021年03月 
    代表者 : 石川 達也, 酒匂 一成, 所 哲也
     
    1.降雨や融雪に伴う表流水や地盤内浸透(鉛直方向・水平方向)が地盤・土要素の水理特性・力学特性に及ぼす影響を定量的に評価するため、加圧給水機能付供試体作製土槽や模型土槽用流水試験装置を新規製作し、当該試験装置の性能確認試験を行い、次年度より実施する室内要素試験・室内模型試験の試験条件について検討した。 2.温暖地域と寒冷地域の気象データや原位置試験結果をもとに、気象条件の違いが地盤の材料特性に及ぼす影響を評価するために、本年度は、原位置試験を実施する温暖地域の試験個所として鹿児島市内のシラス斜面を選定し、新たに切土した現地斜面において、試料採取、簡易貫入試験、現場透水試験を11月と3月に実施した。これにより、透水係数などの計測方法の確立と計測精度の向上を図った。また、採取した土について、含水比、土粒子密度、粒度などの土の基本的物理量に関する土質試験を実施し、各種データの収集を開始した。 3.降雨量および融雪量の積雪浸透による流出の時間的遅れを考慮した積雪浸透モデルを提案した。また、降雨・融雪時の斜面崩壊現象の支配要因(素因・誘因)の特定及びその依存度を定量化するため、実物大模型斜面における地温・含水比分布等の長期計測結果を、提案する積雪浸透モデルを導入した熱伝導・飽和/不飽和浸透連成解析を用いて解析した。この結果、当該解析手法で、斜面内の地温・土壌水分の経時変化や雨水・融雪水の浸透挙動を再現可能なことを示した。
  • 凍土方式遮水壁の凍土・未凍土境界における遮水性劣化の防止技術の開発
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2017年04月 -2020年03月 
    代表者 : 伊藤 譲, 所 哲也, 石川 達也
     
    (1)凍土壁に接する未凍土の構造と透水性の評価:研究初年度に導入した中型水平凍結実験装置を用いて、0℃一定温度に管理された低温チャンバー内で水平方向凍結融解・ 透水実験を実施した。当初は予圧密圧力と実験圧力を様々に変化させる予定であったが、2種類の土に対する同じ条件による実験を繰り返した。供試体中に発生するクラックの発生状況については、当初のインターバルカメラによる撮影では結露が防げないために、インターバルカメラによる観察は次年度に持ち越し、今年度は手動による定点観測を行った。凍結融解実験において、凍結前の未凍土、供試体が部分的に凍結した時,完全凍結後の完全融解時の透水係数を鉛直方向の変水位透水実験から測定する手順は確立できた。しかし、実験期間が1週間程度と短いために、凍土が成長する過程で透水係数を測定しているので、凍土が吸水する水分を控除することが困難であり、透水係数の測定値の精度に課題が残る。
    (2)0℃付近での凍土の透水係数の測定とその推定方法:凍土透水試験、物理試験を継続して実施するとともに、多角的に得られた凍土透水係数と物理定数の相関性を分析し、凍土透水係数の推定手法を構築する事が目的であり、今年度は、従来の凍土透水係数の測定法よりも正確で迅速性が期待できる「遷移パルス法」を試みた。その結果、凍土の透水係数の測定が可能であることを確認できた。
    (3)凍上・凍結融解を受ける凍土遮水壁の地下水流浸透解析手法の確立:模型試験結果及び要素試験結果との連携をとりながら、凍上・凍結融解や水平クラックの発生に伴う凍土壁の遮水性の劣化を考慮可能な2次元熱伝導・浸透連成解析プログラムを開発した。この結果、模型試験や要素試験で確認された温度変化、含水比変化、凍上融解に伴う透水性の変化が表現可能となり、熱物性値及び透水性の異なる凍土壁互層地盤における地下水流の浸透状況の把握が可能になった。
  • 多相力学・マルチスケール分析による気候変動下の高緯度寒冷地盤の広域災害リスク評価
    日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2016年04月 -2020年03月 
    代表者 : 石川 達也, 西村 聡, 磯部 公一, 清水 康行, 山田 朋人, 川口 貴之, 川尻 峻三, 川端 伸一郎, 所 哲也
     
    1.ミクロ(地盤要素)モデルの発展・実証: 凍結融解とそれに伴う地盤の不安定化を解析するために必要な土・水・熱連成弾塑性モデルの構築に向け、凍結融解時の土の挙動を要素レベルで観察する新しい試験方法を考案し、モデル化への提案を行った。また、不飽和凍土の含水量の温度依存性を定量化し、不飽和凍土のSFCCをSWCCに基づいてモデル化した。 2.メソスケール問題の現象分析及びミクロモデルの精度検証: 降雨や融雪による土構造物中の間隙水圧増加・法面不安定化をより正確に予測するため、従来の不飽和浸透流解析に加え、空気相の圧縮・移動を考慮する二相系の浸透流解析や、積雪浸透による流出の時間的遅れを考慮した熱伝導・飽和/不飽和浸透連成解析を実施し、複数のサイトで長期モニタリングを行った結果に照らし、それぞれの適用性を明らかにした。 3.気候変動予測を考慮した地盤応答の広域アップスケーリング方法論の構築: 過去の土砂災害の事例分析や気象条件や地形地質条件を仮定したパラメトリックスタディを行い、数値解析により定まる土砂災害発生危険度基準線(CL)の適用性を検討した。その結果、市町村が定めるCLを基に地形地質条件等が異なる種々の斜面に対して融雪時や豪雨時を対象としたCLの設定が可能であることを示した。 4.高緯度気候-地盤マルチスケールモデルのプロトタイプの開発: 北海道を対象とした高解像度気象・水文場を力学的ダウンスケールにより作成し、気候変動を想定したパラメトリックスタディを実施した。その結果、融解期に加え、凍結初期も融雪水の浸透により斜面が不安定化し易くなることを示した。さらに、気象データ・DEMデータを入力とする広域降雨浸透・流出解析及びその出力を入力とする狭域斜面安定解析の連携性を高め、地表流を考慮した豪雨時の斜面崩壊の広域リスク評価手法を開発した。
  • 日本学術振興会:科学研究費助成事業 特別研究促進費
    研究期間 : 2018年10月 -2019年03月 
    代表者 : 高橋 浩晃, 勝俣 啓, 大園 真子, 橋本 武志, 青山 裕, 酒井 慎一, 松本 聡, 岡田 知己, 小菅 正裕, 寺川 寿子, 飯尾 能久, 中尾 茂, 上嶋 誠, 柴田 智郎, 大津 直, 高井 伸雄, 飯場 正紀, 渡部 要一, 菊地 優, 岡崎 太一郎, 白井 和貴, 西村 裕一, 石川 達也, 高瀬 裕也, 永井 宏, 宮森 保紀, 三宅 弘恵, 松島 信一, 浅野 公之, 重藤 迪子, 卜部 厚志, 前田 宜浩, 石澤 友浩, 廣瀬 亘, 小山内 信智, 山田 孝, 笠井 美青, 檜垣 大助, 風間 基樹, 千木良 雅弘, 渦岡 良介, 竹林 洋史, 木村 誇, 石丸 聡, 岡田 成幸, 内田 賢悦, 有村 幹治, 植松 武是, 多々納 裕一, 梶谷 義雄, 能島 暢呂, 田村 圭子, 中村 洋光, 戸松 誠
     
    平成30年北海道胆振東部地震とその災害に関する総合調査を実施した。大きな人的被害を出した厚真町の同時多発斜面崩壊では、周辺火山の噴火により厚く堆積した火砕降下物の底面に粘土化したすべり面が確認された。震源近くでは距離減衰式より大きな速度加速度が観測され、むかわ町の建物被害は地盤構造による地震動の増幅が影響しいる可能性が示された。札幌市内の住宅地で発生した液状化は、密度の小さな火山灰での谷埋め盛土と高い地下水位が関与している可能性が示された。道内全域停電が社会インフラや社会経済活動に与えた実態が明らかにされた。住民も対象とした成果報告会を開催し研究成果の社会還元を行った。
  • 日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 川端 伸一郎, 亀山 修一, 石川 達也, 佐藤 厚子, 高見 雅三
     
    本研究では,凍上被害の実態を取りまとめ,設計に加味すべき条件および新たな評価手法について検討した.総延長800kmの道路において路面状態を調査し,土工区分(切土か盛土か)と凍結指数が凍上被害に関係することを明らかにした.凍上被害箇所から採取した51種類の路床土の特徴を示した.全国323地点の凍結指数を調べ,その地域特性を明らかにした.また,100年分以上の気温データから凍結指数の長期変動特性を示した.舗装の目視点検の方法の違いが,その評価精度に与える影響を明らかにした.
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 石川 達也, 森井 俊廣, 所 哲也
     
    北海道は、土地利用形態や季節変化に伴う地盤の保水・浸透特性の変動が一年を通して極めて大きいため、気候変動に関連した集中豪雨時に土砂災害発生の拡大要因となる可能性がある。本研究では、土砂災害発生の判断基準となり得る降雨・融雪水の地盤内浸透率に着目し、その支配要因を積雪・植生状況、降雨強度・融雪速度、土質、地盤の含水・凍結状態から体系的に評価して地盤内浸透率の定量化手法を提案するとともに、積雪・植生等地表面の状態を考慮して植生・積雪を数値解析上の要素と考えた場合の地表流・地盤内浸透流特性の数理モデル化方法を開発し、積雪寒冷地特有の事象を踏まえた連成解析型積雪寒冷地斜面安定性評価手法を構築した。
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2014年04月 -2017年03月 
    代表者 : 伊藤 譲, 石川 達也, 所 哲也, 大西 有三
     
    福島第一原発において凍土遮水壁の建設されている地盤は砂質土と泥岩層からなり,大量の地下水が流れている.そこで,遮水壁が本当に完成可能であるか,完成後の凍土壁は十分な遮水性を有するのか,余震等で電源が喪失して凍土が融解した場合にはどうなるのか等の疑問が示されていた. 本研究において,これら3点について検討した結果,次のような結論が得られた.(1)従来用いられている限界流速の理論式と数値計算,モデル実験結果が良く一致した.(2)凍土の透水係数を精度よく測定できる実験方法を開発した.(3)凍結融解土の透水係数を新たに開発した実験装置で検討し,凍結融解土の透水係数の予測方法を提案できた.
  • 日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2014年04月 -2017年03月 
    代表者 : 川口 貴之, 所 哲也, 石川 達也, 中村 大
     
    本研究では,寒冷地における埋設管の損傷リスクを評価するため,舗装路下にある水道管周辺の詳細な温度分布や常時の土中土圧,更には車両通過に伴う地盤内増加応力の季節変化を計測した. その結果,これらが地盤の凍結融解で大きく変化することを明らかにした.また,車体重量が大きくなると地盤内増加応力も増大するが,その比率も凍結融解に伴って変化することや,地盤内での荷重分散についても凍結融解に伴って変化することを明らかにした.
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2012年04月 -2015年03月 
    代表者 : 石川 達也, 木村 一郎
     
    本研究では、積雪寒冷地で発生する可能性のある相変化依存型土砂災害を想定して、凍結融解作用を受ける地盤の浸透侵食挙動の評価を対象とした模型試験法を確立するとともに、凍結融解地盤の浸透侵食特性に及ぼす影響因子として、流水条件、凍結融解条件、地盤材料の凍上性や浸透・保水性が強く影響することを示した。また、凍結融解現象を含む幅広い土砂・流体連成問題に適用可能な解析手法を開発し、当該解析手法を用いて浸透流のある凍結融解地盤で生じる可能性のある相変化依存型土砂災害発生機構を検討可能であることを検証した。
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2011年04月 -2015年03月 
    代表者 : 石川 達也, 三浦 清一, 山下 聡, 川端 伸一郎, 川口 貴之, 所 哲也, 北村 良介, 木村 一郎, 西本 聡
     
    本研究では、集中豪雨など短時間で多量の雨水浸透や融雪水の流入がある際に、積雪寒冷地で発生する可能性のある凍結融解・流水侵食複合型地盤災害を想定して、凍結融解作用・流水侵食作用を受ける地盤・土構造物の力学挙動を対象とした室内要素試験方法・模型試験方法・数値解析方法を確立してその力学的劣化機構を解明するとともに、過去の気象データから今後道内で起こりえる気候変動を予測した上で、それにより積雪寒冷地で発生する可能性のある新しい地盤災害形態を推測し、その危険性を評価する手法を開発した。
  • 日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2011年04月 -2014年03月 
    代表者 : 三浦 清一, 石川 達也, 川村 志麻, 横浜 勝司
     
    本研究は,凍結融解作用を受ける破砕性火山灰地盤の力学特性の変化に着目して,積雪寒冷地にある火山灰質粒状層を含む帯水斜面の崩壊のメカニズムを解明し,実務における斜面危険度評価法を提案することを目的とした。高精度の斜面崩壊予測法を提案するためには,実物大斜面における崩壊時の力学挙動評価が必要となる。一連の研究では,申請期間3年間に亘り,締固め条件や境界条件の異なる実物大盛土斜面を構築し,その動態観測ならびに崩壊実験を実施した。併行して,新たに試作した凍結融解履歴型繰返し不飽和三軸試験装置による室内要素試験,室内模型実験を実施し,それらの結果を考慮した高度な斜面危険度評価法を提案した。
  • 日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2010年 -2012年 
    代表者 : 澁谷 啓, 川口 貴之, 鳥居 宣之, 木幡 行宏, 石川 達也, 齋藤 雅彦, 中村 努, 加藤 正司
     
    本研究では,ジオシンセティックスを用いたL型排水盛土防水工を,補強土(テールアルメ)壁工法に適用し優れた効果を確認した.谷埋め盛土など背面側からの浸透水が懸念される箇所で有効に機能するものと思われる.排水機能が健全な状態では震度 6 強~7 強震動観測地区であっても被災を免れると考えられる.また,スラグおよびスラグ混合土を用いた土層の変位量が一般土を用いた場合より小さいこと,また,スラグ補強土壁の盛土造成時の締固め度 80~85%程度でも安全率が Fs=1.6 以上確保できた事実よりスラグ補強土壁が施工性に安全であると判断される.
  • 凍結融解地盤の温度依存型透気係数推定方法の提案
    北海道ガス:平成22年度北海道ガス大学助成制度
    研究期間 : 2010年04月 -2011年03月 
    代表者 : 石川 達也
  • 凍結融解地盤の温度依存型透気試験方法の開発
    北海道ガス:平成21年度北海道ガス大学助成制度
    研究期間 : 2009年04月 -2010年03月 
    代表者 : 石川 達也
  • 凍結融解作用を受ける斜面の崩壊予知・災害危険度評価システムの確立
    国土交通省:道路政策の質の向上に資する技術研究開発
    研究期間 : 2007年04月 -2010年03月 
    代表者 : 三浦 清一
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2009年 -2010年 
    代表者 : 石川 達也, 山下 聡
     
    1.凍結時および融解時の不飽和地盤の透気係数を計測・評価するため、凍上性・非凍上性地盤材料(火山灰質土と豊浦砂)の凍結融解不飽和透気試験を室内及び屋外で実施した。その結果、以下のような知見が得られた。(1)試験時の含水比が透気係数に及ぼす影響は土質によって異なり、火山灰質土では、飽和度60%以下では飽和度の上昇に伴い透気係数が高くなるというという豊浦砂と逆の傾向が得られた。これは、締固め時の含水比変化に伴う土の骨格構造の変化に起因すると考えられ、締固め含水比を土質に応じて変えることで、地盤材料の透気性を制御できる可能性がある。(2)凍上性火山灰質土においても、非凍上性の豊浦砂と同様、地温0℃付近で透気係数は大きく変化した。しかしながら、同一飽和度(空気間隙比)で透気係数を比較した場合、豊浦砂では凍土の透気係数は未凍土よりも若干低くなったが、火山灰質土では、地温の低下に伴い透気係数は上昇した。また、凍上時の火山灰質土の透気係数は非凍上時よりも高くなった。これらは、両者の含水比の違いによる未凍結時の土壌水分挙動、土の骨格構造及び間隙水の氷結様式の違いに起因すると考えられる。(3)凍上性火山灰質土では、凍結融解が繰り返され飽和度が一定値以上に増加すると間隙水の増加により空気は透り難くなり、加えた水分の凍結・凍上によりさらに透気係数は低下する傾向が確認された。 2.開発した透気試験方法によれば、不飽和状態で繰返し凍結融解作用を受ける凍上・非凍上性地盤材料の温度依存型透気係数の評価が可能であること、および不飽和地盤の透気係数は、温度依存性を示すとともに、地盤材料の凍上性、保水性・透水性、締固め特性の影響を多大に受けることが明らかになった。積雪寒冷地で地盤の透気性を検討する場合、これらの要因を考慮することが精確な挙動予測に重要となる。
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2008年 -2010年 
    代表者 : 石川 達也, 三浦 清一, 亀山 修一, 川端 伸一郎, 小野 丘, 安倍 隆二, 関根 悦夫, 八谷 好高
     
    本研究では、凍結融解作用を受ける粒状路盤の力学特性の試験方法を提案するとともに、凍結時及び凍結融解後の粒状路盤の力学挙動を把握し、舗装構造の理論的設計方法を用いて、凍結融解に伴う粒状路盤の性能変化が道路舗装の疲労寿命に及ぼす影響を検討した。この結果、粒状路盤が凍結融解作用を受けた場合、支持力特性のような力学的な性能が変化し、疲労寿命のような走行路構造の長期性能に強く影響を及ぼすことを明らかにした。
  • 日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2007年 -2009年 
    代表者 : 三浦 清一, 赤川 敏, 石川 達也, 川村 志麻, 岩花 剛, 伊東 佳彦, 西本 聡
     
    積雪寒冷地で斜面崩壊を誘発する因子間の力学作用を解明し、凍結融解や融雪・降雨等に伴う構成地盤材料の力学特性の変化に着目した、凍結融解・降雨複合型斜面崩壊現象の簡易災害危険度評価式を提案するとともに、気象・地盤・過去の災害事例等の異種情報を統合した地盤情報データベースを作製し、蓄積された情報と簡易災害危険度評価式を利用して凍結融解作用を受ける斜面の崩壊予知や災害危険度の評価を行うシステムを開発した。
  • 寒冷地用舗装構造の路盤・路床の変形挙動評価試験法に関する研究
    北海道ガス:平成19年度北海道ガス大学助成制度
    研究期間 : 2007年04月 -2008年03月 
    代表者 : 石川 達也
  • 日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2006年 -2007年 
    代表者 : 石川 達也, 三浦 清一, 横浜 勝司, 関根 悦夫
     
    1.飽和・不飽和粒状路盤の繰返し塑性変形挙動に及ぼす移動荷重の影響評価 供試体の飽和度を変更可能な2次元土層を具備したローラー移動載荷試験装置を開発し、移動荷重を受ける飽和・不飽和路盤の力学特性評価に適した模型試験方法を確立した。また、開発した試験装置を用いて、異なる荷重制御方法(移動載荷・定点載荷)で、異なる含水状態(気乾・浸水)の切込砕石路盤の繰返し載荷試験を行った。その結果、粒状路盤の塑性沈下は含水状態の変化に強く影響され、その傾向は移動荷重載荷時に一層顕著になること、および同一含水状態で異なる荷重載荷方式の繰返し載荷試験結果を比較した場合、両者の累積沈下量の比は含水状態の違いによらずほぼ一定となることを明らかにした。 2.飽和・不飽和路盤材の繰返し塑性変形特性に及ぼす主応力軸回転の影響評価 主応力軸回転の影響を評価可能な多重リングせん断試験機を用いて、移動荷重を受ける飽和・不飽和路盤材の力学特性評価に適した試験方法を提案した。また、異なる荷重制御方法で、異なる含水状態の切込砕石の多重リングせん断試験を行った。その結果、気乾試料に比べ浸水試料の方が繰返し載荷試験で発生する累積鉛直ひずみは大きいこと、定点載荷より移動載荷方式の繰返し載荷試験において供試体の飽和化が累積鉛直ひずみに及ぼす影響は顕著に現れること、および多重リングせん断試験結果は上記1.の模型試験結果と定性的に一致し、定量的にもほぼ一致することを明らかにした。 3.移動荷重下の飽和・不飽和粒状路盤の繰返し変形挙動予測とその性能評価手法の確立 繰返し移動荷重作用下にある飽和・不飽和粒状路盤の変形挙動予測に適用可能な数値解析モデルを開発するために、上記1.と2.の結果から粒状路盤材の要素試験結果の適用方法について検討した。この結果、移動荷重繰返し載荷時の気乾・浸水状態にある粒状路盤の累積塑性沈下量の簡易推定方法を提案した。
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2004年 -2006年 
    代表者 : 三浦 清一, 赤川 敏, 石川 達也, 横浜 勝司, 川村 志麻
     
    1.破砕性地盤材料の凍結融解現象と静的力学特性に及ぼす影響の解明 (1)凍結融解履歴を受けると,その構成粒子の破砕性は顕著となり,そのことを反映して火山灰土の変形性や強度は低下する。 (2)凍結融解履歴が粒子破砕性に及ぼす影響は定圧密レベルで顕著となり,ある圧力以上ではその影響は消失する。このことは斜面の表層部において地盤構成材料の力学的劣化がもたらされやすい傾向があることを示唆している。 2.凍結融解履歴による破砕性地盤材料の動的変形・強度特性の変化とその評価法 (1)動的せん断弾性係数は凍結融解履歴によって確実に変化し,その履歴回数の増加とともに最大10%程低下することが示された。一方,履歴減衰比は凍結融解の影響をほとんど受けない。 (2)液状化強度については,凍結融解により最大20%程度の低下が認められる。これらの動的力学特性に及ぼす影響の違いは,構成粒子の硬度によるものであるが,凍結融解履歴による堆積構造の変化の貢献が大きいのではないかと考察されている。 3.降雨による破砕性帯水斜面の崩壊機構とその解析 (1)斜面崩壊に関わる降雨の影響は発生間隙水圧と飽和度(土壌水分)で評価可能であるが,その中で,飽和度の適切な評価は崩壊パターンや時期を推定する上で重要であることが示された。 (2)斜面内の不透水層の位置と形状は斜面安定性に決定的な影響を及ぼす。 4.破砕性帯水斜面の崩壊因子とその相互関係に関する数値解析 (1)間隙水の凍結で生じる凍結圧を考慮するために導入した熱膨張球要素に基づく解析は,凍結融解作用によりもたらされる地盤の間隙比あるいは粒子構造が変化する事実を定性的に説明することができる。 (2)火山灰地盤の斜面崩壊挙動を推定するための不連続体解析手法は、降雨浸透による地盤の不均質性やダイレイタンシー挙動が適切に評価できれば、有用な評価法となる。
  • 日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2003年 -2004年 
    代表者 : 石川 達也, 三浦 清一, 横浜 勝司, 関根 悦夫
     
    1.移動荷重作用下にある粒状構造物の変形挙動の解明 (1)粒状路盤構造の模型試験結果より、移動荷重は定点荷重に比べ繰返し塑性変形量の大きくなることがわかった。また、礫材の粒度分布の違いによる繰返し塑性変形量の違いが定点載荷よりも移動載荷でより顕著に表れることから、粒状路盤構造の繰返し変形特性を検討する際の移動載荷試験の有用性を示した。 2.数値解析による粒状構造物の力学挙動推定法の提案 (1)不連続体解析により粒状路盤構造の挙動解析を行い、構成粒子のモデル化方法に起因する解析精度の向上について検討した。その結果、粒子形状が解析精度に強く影響を及ぼすことを定量的に示すとともに、実粒子形状を模擬した不連続体解析による粒状構造物内部の応力状態推定法を提案した。 (2)繰返し荷重作用時の粒状構造物の変形挙動予測に対する礫材の要素試験結果の適用方法について検討した結果、礫材の累積ひずみ特性を考慮した有限要素法の静的線形弾性解析による粒状路盤構造の挙動解析法を確立し、繰返し塑性変形量の簡易推定方法を提案した。 3.移動荷重作用下にある粒状構造物の変形挙動予測に適した要素試験方法の確立 (1)礫材の多重リングせん断試験と三軸圧縮試験を行い、せん断試験法の違いが礫材の力学特性に及ぼす影響について検討した結果、せん断中の主応力回転や中間主応力の変化が礫材の力学挙動に強い影響を及ぼすことを示した。 (2)移動荷重作用時に模型試験で粒状路盤構造が受けた応力履歴を模擬して多重リングせん断試験を行った結果、従来の三軸圧縮試験に比べ、多重リングせん断試験結果が模型試験で得られた粒状路盤構造の繰返し塑性変形挙動に近いことを示し、移動荷重繰返し作用下の粒状構造物の変形挙動予測に適した粒状地盤材料の材料特性の評価方法として多重リングせん断試験が有効であることを示した。
  • 凍結融解地盤の性能評価・挙動予測技術の開発
    研究期間 : 2004年
  • 粒状構造物の力学的安定性に関する研究
    研究期間 : 2002年
  • Study on dynamic stability characteristics of granular materials
    研究期間 : 2002年

教育活動情報

主要な担当授業

  • 公共政策特別研究ⅡA
    開講年度 : 2018年
    課程区分 : 専門職大学院
    開講学部 : 公共政策学教育部
  • 大学院共通授業科目(教育プログラム):JICA開発大学院連携プログラム
    開講年度 : 2018年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : Disaster prevention; Natural disaster; Flood; Heavy rainfall; Tsunami; Liquefaction; Earthquake; Japan’s ODA
  • 公共政策特別研究Ⅰ
    開講年度 : 2018年
    課程区分 : 専門職大学院
    開講学部 : 公共政策学教育部
  • 職業実習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 職業実習 職業選択 大学と社会との関係
  • 土の力学Ⅰ
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 土の基本的性質,土の分類,透水,地盤内応力,圧密,締固め
  • 土の力学Ⅱ
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 地盤のせん断強さ,土圧,土留め構造物,斜面の安定,地盤の支持力,構造物基礎
  • 環境フィールド学実習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 測量 現地踏査 基準点測量 地形測量 実務能力
  • 土の力学演習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 土の基本的性質、土中水と浸透、地盤内応力と変形、土の圧縮特性、圧密、応力とテンソルの基礎、せん断、排水強度と非排水強度、土圧、斜面の安定、地盤の支持力
  • 技術者倫理学
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 技術者倫理,倫理規定,土木技術史,倫理問題事例研究
  • 技術政策学
    開講年度 : 2018年
    課程区分 : 専門職大学院
    開講学部 : 公共政策学教育部
    キーワード : 科学技術、テクノロジー・アセスメント、国土開発、環境技術、宇宙政策、原子力安全、エネルギー政策、自然再生エネルギー、防災政策、廃棄物処理・管理、インフラ整備、安全規制、技術基準


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