地盤の応力と変形

[III-466] Numerical simulation of reliquefaction of sand by 3D Discrete Element Method

*森本 時生¹、大坪 正英²、古関 潤一¹ (1. 東京大学大学院社会基盤学専攻、2. 東京大学生産技術研究所)

Keywords:liquefaction, reliquefaction, Discrete Element Method, DEM, Coordination number, preshearing

During 2010-2011 Canterbury Earthquake and 2011 Great East Japan Earthquake, reliquefaction phenomenon was observed many times. After these earthquakes, there are of increasing interests on liquefaction resistance of sand which experienced preshearing. Based on the background, in this study, 3D Discrete Element Method was employed to reveal the fundamental changes in sand after preshearing and their relations to liquefaction resistance. By DEM simulations, this study showed that sand which was presheared more largely has more unstable particles which have smaller coordination numbers and this change could be related to the significant decrease in liquefaction resistance.