地震作用下含地下水边坡动力响应耦合分析

运用有限差分软件FLAC3D，建立赋含地下水的三维土质边坡模型，并基于Byrne动孔压增长模型，研究了不同地下水位下边坡的加速度、速度、频谱地震动力响应规律；分析了超静孔隙水压力变化规律。结果表明:在地震作用下，边坡对地震动加速度具有垂直放大效应和临空面放大效应，随着距坡面距离的减小，坡内加速度放大系数呈先减小后增大的趋势，含地下水边坡的放大作用大于无水边坡；速度放大系数沿坡面高程增加而增加，坡内速度放大系数变化规律与加速度一致；边坡主要对地震动的低频成分起放大作用，傅里叶谱峰值随地下水位升高而降低；边坡坡脚位置处超静孔隙水压力最小，但超孔比最大，极易发生液化。

Analysis on Dynamic Response Coupling of Slope with Groundwater under Earthquake

A three-dimensional model of a soil slope containing groundwater was established by finite difference software FLAC3D. Based on the Byrne model of dynamic pore-pressure, the acceleration, velocity and spectrum seismic dynamic response law of the slope under different groundwater levels were studied, and the change law of excess pore water pressure of the slope was analyzed. The results show that under the action of earthquake, the slope has vertical amplification effect and air face amplification effect on the ground motion acceleration. With the decrease of the distance from the slope, the acceleration amplification coefficient in the slope first decreases and then increases. Moreover, the amplification effect of the slope with groundwater is greater than that of the slope without water. With the slope elevation increasing, the velocity amplification coefficient increases, and the change law of velocity amplification coefficient in slope is consistent with that of acceleration. Typically, the low-frequency components of ground motions were mainly amplified by the slope, and the peak of Fourier spectrum decreases while the ground water level increases under earthquake. At the foot of the slope, the excess pore water pressure is the smallest, but the excess pore pressure ratio is the largest. As a result, liquefaction is easy to occur.