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| ANALYSIS OF LANDSLIDE RESPONSES OF A TYPICAL HIGH HILL-RIVER VALLEY FIELD NEAR NATIONAL ROAD G213 DURING WENCHUAN EARTHQUAKE |
| YANG Changwei，ZHANG Jianjing |
| (School of Civil Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China) |
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Abstract A high steep hill with river valley near National Road G213 is used as a prototype. A full process from initial deformation to sliding of the slope during ground shaking is simulated by a new discrete element method—continuum-based discrete element method(CDEM). Combining with shaking table test results，seismic landslide responses of accumulation body of the high steep slope are analyzed. The analytical results are as follows. The stress concentration phenomenon appears at the top of the accumulation body firstly；and then some tension failure points and shear failure points appear there，which expands toward the toe of the accumulation body from the top of that along the accumulation body-bed rock structural plane. At the same time，the number of tension failure points gradually increases. At last，the toe of the accumulation body-bed rock structural plane breaks；and then the accumulation body shears out from the toe，which results in the landslide. The starting time of landslide and the arrival time of peak ground acceleration(PGA) are synchronous or the former lags behind the latter slightly. In the high steep area，based on the input seismic wave，regardless of on the slope or inside the slope，peak acceleration is amplified as elevation increases. Generally speaking，amplification of the vertical peak acceleration is larger than that of horizontal peak acceleration；and the amplification of peak acceleration on a slope is larger than that inside the slope. In the river valley topography，based on the input seismic wave，regardless of the river valley or the backsides，peak ground acceleration is also amplified as elevation increases. There are some influence scopes of river valley on acceleration amplification effect. In this scope，the amplification of the horizontal peak ground acceleration is larger than that of the vertical peak ground acceleration. The amplifications of accelerations have obvious directivity of topographic effects，which are related to the gradient of bank sides. Distribution of acceleration amplification effect is nonuniform in river valley；and the smaller the distance to bank sides is，the stronger the acceleration amplification effect is.
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Received: 29 October 2012
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2013, Vol. 32 
