堆积型滑坡地震响应的离心模型试验

Centrifuge Model Test on the Seismic Response of Colluvial Landslide

基于离心振动台模型试验,采用Taft波激励,不断增大其幅值,研究不同强度地震波作用下堆积型滑坡地震响应特征,对比分析了汶川地震清溪台站基岩波结果的异同.结果表明:坡面水平向和竖直向峰值加速度放大系数均随坡高增加而增大,呈现高程放大效应;坡体内水平向峰值加速度放大系数分布与坡面不同;坡面对输入地震波有反射作用并呈现坡面浅表放大效应;基岩水平向加速度随高程增加存在增大现象,与地震动输入相比,均有缩小现象.同一高程处,坡面水平向与竖直向、坡体内及基岩水平向峰值加速度放大系数随地震波幅值的增大其变化规律不同.

Seismic response behaviors of colluvial landslide were discussed by inputting Taft wave with different intensities based on dynamic centrifuge model test. Results under Taft wave and Qingxi wave were comparatively analyzed. Results show that both the horizontal and vertical peak ground acceleration （PGA） amplification coefficients at slope surface increase with the increasing of height. The landslide shows an obvious altitude amplification effect. The distributions of horizontal PGA amplification coefficients in the landslide body are different from those of the landslide surface. The landslide surface has an obvious reflect effect on input seismic wave, and it shows the surface effect. The bedrock also has amplification effect along with the height of the landslide, and it has reductive effect compared with the input seismic waves. At the same height, the PGA amplification coefficients at landslide surface, landslide body and bedrock have different distributions with the increasing of earthquake amplitudes.