Performance information

• Distinct element analysis of overburden subjected to reverse oblique-slip fault　　　　　　　　　　　　　　　
  Hisashi Taniyama
  JOURNAL OF STRUCTURAL GEOLOGY, Volume：96, First page：90, Last page：101, Mar. 2017, [Reviewed]
  The deformation of overburden subjected to a reverse oblique-slip fault was examined in this study using the distinct element method, and the results were compared with the shears measured at the Nojima fault during the 1995 Hyogoken Nanbu earthquake. Shear deformation was found to occur mainly on the footwall side of the overburden in a narrow zone and to be caused by the reverse fault component. The stress due to both the reverse fault and strike-slip movement led to the development of failure surfaces with a convex-upward shape in cross section and an en echelon pattern in plan view. The width of the zones of high incremental strain obtained in the present analysis was found to be in agreement with the observed width of the shears; however, the observed and simulated intervals and orientations of the shears did not agree. The simulation results suggest that short shears that form in the deep part in the early stages of the deformation join to form longer shears as they propagate toward the surface. (C) 2017 Elsevier Ltd. All rights reserved.
  PERGAMON-ELSEVIER SCIENCE LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.jsg.2017.01.007
  DOI ID：10.1016/j.jsg.2017.01.007, ISSN：0191-8141, Web of Science ID：WOS:000397683800006
• Analysis of a buried pipeline subjected to fault displacement: A DEM and FEM study　　　　　　　　　　　　　　　
  Md. Aftabur Rahman; Hisashi Taniyama
  SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, Volume：71, First page：49, Last page：62, Apr. 2015, [Reviewed]
  Buried pipelines are commonly used to transport oil, water, sewage, and natural gas and are referred as lifeline systems. The 3D discrete element method (DEM) analysis was carried out to examine the response of buried pipeline owing to fault movement. Approximately 1.8 million spherical particles, which were considered to represent soil and a hollow circular pipe, were placed at a shallow depth in the proposed numerical model. The DEM simulation was performed for the sedimentation of soil particles, and fault displacements were subsequently assigned to the model. The force-displacement relation between pipes and particles is important in the modeling and design of buried pipes in the vicinity of faults. The present study discusses the force-displacement relation between pipes and particles in the axial and vertical directions for fault movement. This relation reveals the strain softening behavior of particles near the fault crossing point. The interaction between soil particles and pipe elements can be understood from this numerical simulation. Particles push the pipes and have a greater effect near the rupture point Finally, a parametric study was performed using different pipe properties, and the responses were analyzed. (C) 2015 Elsevier Ltd. All rights reserved.
  ELSEVIER SCI LTD, English, Scientific journal
  DOI：https://doi.org/10.1016/j.soildyn.2015.01.011
  DOI ID：10.1016/j.soildyn.2015.01.011, ISSN：0267-7261, eISSN：1879-341X, Web of Science ID：WOS:000353426200006
• Numerical analysis of overburden soil subjected to strike-slip fault: Distinct element analysis of Nojima fault　　　　　　　　　　　　　　　
  Hisashi Taniyama
  ENGINEERING GEOLOGY, Volume：123, Number：3, First page：194, Last page：203, Nov. 2011, [Reviewed]
  A distinct element method analysis is carried out to examine the development of shear bands in overburden soil subjected to a strike-slip fault. About 2.3 million spherical particles are used in the analysis and the results are compared with the shears observed at the Nojima earthquake fault during the 1995 Hyogoken Nanbu earthquake. En echelon shears and secondary shears which strike at lower angles to the basement fault - typical in strike-slip faults - are observed in the numerical analysis. Simple shear in the horizontal plane and drag due to the dependence of velocity on depth are confirmed to control the helicoidal shape of Riedel shears. Rotation of the compressional direction toward the fault strike as a result of slip along Riedel shears is also verified. It is found that the compressional direction is more horizontal within the area enclosed by Riedel shears than in outside areas and that these compressional directions produce secondary lower-angle shears that are less helicoidal. It is shown that the formation of column-like structures of particles and their subsequent buckling play significant micromechanical roles in three-dimensionally wrenched shears. The results of the numerical analysis, such as shear intervals and striking angles, show a resemblance to observational results at sites where sediment contains coarse grains and is subjected to strike slip with a small dip component, although they are not exactly the same as those observed at locations with similar overburden thicknesses. (C) 2011 Elsevier B.V. All rights reserved.
  ELSEVIER SCIENCE BV, English, Scientific journal
  DOI：https://doi.org/10.1016/j.enggeo.2011.08.003
  DOI ID：10.1016/j.enggeo.2011.08.003, ISSN：0013-7952, Web of Science ID：WOS:000297182200005

• Stress change history of the 2000 tottori-ken-seibu earthquake and near-field strong motion　　　　　　　　　　　　　　　
  Hisashi Taniyama
  Journal of Structural and Construction Engineering, Volume：73, Number：629, First page：1201, Last page：1208, Jul. 2008
  The stress change history of the 2000 Tottori-ken-seibu earthquake is determined using the strong motion records. The result shows large stress drop in the upper central part of the fault. Negative stress drop is observed at the NW and SE sides of the fault at the depth of between 5 and 10 km. The slip distributions agree with those obtained from kinematic models. The stress-time histories in the high stress drop zones show predominantly monotonic stress drop. The result indicates that relatively high peak velocities observed at the stations near the fault are due to the high stress drop and the directivity effect. The ground motion inferred from the obtained stress change shows high peak velocity around the source area.
  Japanese
  DOI：https://doi.org/10.3130/aijs.73.1201
  DOI ID：10.3130/aijs.73.1201, ISSN：1340-4202, SCOPUS ID：79954540711
• 横ずれ断層によって表層地盤に形成されるせん断帯－DEMによる解析－　　　　　　　　　　　　　　　
  谷山 尚
  Volume：64, Number：3, First page：485, Last page：494, 2008
  DOI：https://doi.org/10.2208/jscejc.64.485
  DOI ID：10.2208/jscejc.64.485, ISSN：1880-604X, CiNii Articles ID：80019628579
• 2000年鳥取県西部地震の断層面上の応力変化と断層近傍の強震動　　　　　　　　　　　　　　　
  Volume：73, Number：629, First page：1201, Last page：1208, 2008
  DOI：https://doi.org/10.3130/aijs.73.1201
  DOI ID：10.3130/aijs.73.1201
• 断層の破壊進展への地盤物性・構造物の影響　　　　　　　　　　　　　　　
  谷山尚
  Volume：5(18年度), First page：632, Last page：633, 2007
• 基盤断層の変位が第四紀地盤上の構造物に与える影響の評価　　　　　　　　　　　　　　　
  岩下和義; 谷山尚; 長田昌彦; 川上英二; 茂木秀則; 斎藤正人
  埼玉大学地域共同研究センター紀要, Volume：7, Number：7, First page：80, Last page：83, 2006
  This article describes the evaluation of ground and structure damages due to active fault displacement. This study was supported by Japan Nuclear Energy Safety Organization (JNES). Three topics are mainly studied, 1. Dynamic properties of granular materials those are the component of soft surface layer, 2. Numerical simulation methods for predicting ground dislocation due to active fault displacement and 3. wave propagation distortion due to existing active fault in soft surface layer.
  Japanese
  ISSN：1347-4758, CiNii Articles ID：120001371321, CiNii Books ID：AA11808968
• 地形、樹木、建物群などの地表面の条件が地震動に与える影響の解明(課題番号 : 14380199)　　　　　　　　　　　　　　　
  川上英二; 渡邉啓行; 茂木秀則; 谷山尚
  Volume：平成14-16年度, 2005
• 地表面での地震動のばらつきと地形・樹木・建物群などの影響の解明　　　　　　　　　　　　　　　
  川上英二; 渡辺啓行; 荒川洋二; 岩下和義; 茂木秀則; 谷山尚; 斎藤正人
  Volume：4, 2005
  ISSN：1347-1945, J-Global ID：200902244211646860
• アレイ観測記録の解析手法の開発・体系化と学内アレイ観測網の拡充(課題番号 : 10450171)　　　　　　　　　　　　　　　
  川上英二; 渡邉啓行; 茂木秀則; 谷山尚; 韓思雄; ハダディ・ハミド・レザ
  科学研究費補助金(基盤研究B)研究成果報告書, Volume：平成10-12年度, 2001
• 断層上の動力学的破壊モデルパラメタの推定法に関する研究　　　　　　　　　　　　　　　
  谷山尚
  Volume：3, First page：541, Last page：546, 2000
  DOI：https://doi.org/10.2208/journalam.3.541
  DOI ID：10.2208/journalam.3.541
• Deformation of sandy deposits by fault movement　　　　　　　　　　　　　　　
  Volume：2209, 2000
• 断層上の動力学的破壊モデルパラメタの推定法に関する研究　　　　　　　　　　　　　　　
  谷山尚
  応用力学論文集, Volume：3, First page：541, Last page：546, 2000
  An inversion method to infer dynamic rupture parameters of earthquake faults is presented. An earthquake fault is divided into subfaults. Assuming that stress drop occurs within the subfault and that stress drop in other area of the fault is 0, the ground motion generated by each subfault is calculated. The seismic wave of an earthquake can be expressed as the sum of the waves of each subfault. The rupture time and the stress drop of each subfault are used as dynamic rupture parameters. I applied the inversion method to a simple model using synthetic seismogram generated numerically by 3-D finite difference method. The inferred parameters are exactly the same as the ones used to calculate synthetic seismogram.
  Japanese
  DOI ID：10.2208/journalam.3.541, ISSN：1345-9139, CiNii Articles ID：120001371036, CiNii Books ID：AA11311063
• 断層上の応力降下過程が断層近傍の地震動に与える影響　　　　　　　　　　　　　　　
  谷山尚
  応用力学論文集, Volume：2, Number：2, First page：523, Last page：531, 1999
  Japanese
  DOI ID：10.2208/journalam.2.523, ISSN：1345-9139, CiNii Articles ID：40005212297, CiNii Books ID：AA11311063
• DEFORMATION OF SANDYDEPOSIT BY REVERSE FAULTING　　　　　　　　　　　　　　　
  TANIYAMA Hisashi; WATANABE Hiroyuki
  Doboku Gakkai Ronbunshu, Volume：591, Number：I-43, First page：313, Last page：325, 1998
  The deformation of sand subjected to reverse fault displacements was investigated by experiments and numerical analysis. Experimental results could be simulated well by elasto-plastic finite element analysis with joint elements which model shear rupture zone. Calculating bedrock fault movement by dynamic model, earthquake fault rupture propagation in sandy deposit was analyzed numerically. The results suggest that earthquake fault rupture may propagate through deposit and reach the ground surface, if the bedrock fault vertical displacement exceeds several percents of the depth of the deposit.
  Japan Society of Civil Engineers, Japanese
  DOI：https://doi.org/10.2208/jscej.1998.591_313
  DOI ID：10.2208/jscej.1998.591_313, ISSN：0289-7806, CiNii Articles ID：10001884513, CiNii Books ID：AN10014020
• 逆断層運動に伴う砂質表層の地盤の変形に関する研究　　　　　　　　　　　　　　　
  渡辺啓行
  土木学会論文集, Volume：591, Number：I-43, First page：313, Last page：325, 1998
  The deformation of sand subjected to reverse fault displacements was investigated by experiments and numerical analysis. Experimental results could be simulated well by elasto-plastic finite element analysis with joint elements which model shear rupture zone. Calculating bedrock fault movement by dynamic model, earthquake fault rupture propagation in sandy deposit was analyzed numerically. The results suggest that earthquake fault rupture may propagate through deposit and reach the ground surface, if the bedrock fault vertical displacement exceeds several percents of the depth of the deposit.
  Japan Society of Civil Engineers, Japanese
  DOI：https://doi.org/10.2208/jscej.1998.591_313
  DOI ID：10.2208/jscej.1998.591_313, ISSN：0289-7806, CiNii Articles ID：10001884513, CiNii Books ID：AN10014020
• 動力学的モデルによる断層近傍の強震動-地下構造の影響を入れたモデル-　　　　　　　　　　　　　　　
  谷山尚
  First page：111, Last page：116, 1998
  CiNii Articles ID：80010719508
• ライフラインの機能損失と復旧過程の耐震診断のための汎用プログラムILASの作成　　　　　　　　　　　　　　　
  川上英二; 谷山尚; 佐藤正行
  Volume：平成5,6年度, 1995

• Analysis of shear bands formed in sedimentary overburden by strike-slip faults　　　　　　　　　　　　　　　
  2008
• Analysis of shear bands formed in sedimentary overburden by strike-slip faults　　　　　　　　　　　　　　　
  2008

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  Competitive research funding
• -　　　　　　　　　　　　　　　
  Competitive research funding