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| DISCRETE ELEMENT SIMULATION OF DEFORMATION AND MOVEMENT MECHANISM FOR TANGJIASHAN LANDSLIDE |
| CAO Yanbo1，DAI Fuchu1，XU Chong1，TU Xinbin1，MIN Hong2，CUI Fangpeng3 |
| (1. Institute of Geology and Geophysics，Chinese Academy of Sciences，Beijing 100029，China；2. State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics，Chinese Academy of Sciences，Wuhan，Hubei 430071，China；3. China University of Mining and Technology，Beijing 100083，China) |
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Abstract Earthquake is considered as one of the main factors of the generation of a landslide which always causes severe disasters. Taking Tangjiashan landslide，a typical bedding rockslide triggered by the Ms 8.0 Wenchuan earthquake，as the study site，and discrete element numerical simulation is carried out to simulate the initial and subsequent movement of the rockslide. It is found that under seismic loading，stress concentration occurred first at the top of the slope and then expanded from the top towards the toe along the sliding plane，sheared out from the toe in the end and resulting in failure of the slope. The simulation of the subsequent movement of the slope shows that the movement mode of Tangjiashan landslide is starting-up→high-speed sliding→colliding down→self-stabilizing. It also shows that some blocks of the surface exhibit horizontal throwing and vertical jumping under seismic loading. Topographic amplification effects are also observed from both acceleration and velocity of the monitoring points of the slope，indicating that the amplification factor of horizontal acceleration exceeds that of vertical acceleration，and the amplification factor of horizontal velocity exceeds that of vertical velocity. By contrasting the amplification effect of structural plane and the underlying bedrock，it is found that there was a high acceleration when the landslide was at the stage of starting-up，and it also shows that the existence of persistent structural plane plays a controlling role in the dynamic response of the rock slope.
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Received: 09 June 2010
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2011, Vol. 30 
