【摘要】 根据汶川地震中滑坡多沿断层分布的特点,利用FLAC有限差分软件建立了一个土质边坡动力数值分析模型,分别研究了具有向前方向性效应、滑冲效应和无速度脉冲的近断层地震动作用下边坡的动力响应。结果表明:含速度脉冲地震动对边坡的破坏作用远强于无速度脉冲地震动,且具有滑冲效应的地震动引起的边坡动力响应稍大于向前方向性效应地震动。近断层地震作用下,边坡水平方向绝对峰值加速度分布存在沿高程放大效应。具有向前方向性效应的地震动会增强边坡加速度的高程放大效应而具有滑冲效应的地震动则在一定程度上削弱了这种放大效应,且边坡中下部绝对峰值加速度值相对于向前方向性效应地震动和无速度脉冲地震动引起的绝对峰值加速度值较大。更多还原

【Abstract】 On the basis of the distribution characteristics of landslides along the fault in the Wenchuan earthquake,the finite difference FLAC program was applied to analyze the dynamic response of the soil slope by using the nonlinear time-history method.Near-fault ground motions with the forward directivity effect,fling-step effect,and non-pulse were selected as seismic inputs.The results show that the potential damages to slopes caused by pulse-like ground motions are significantly greater than the cases with non-pulse ground motions,and the dynamic responses of slopes caused by fling-step pulses are slightly larger than those associated with forward directivity pulses.An amplification effect of the peak horizontal acceleration is apparent in the vertical direction of slope,and the amplification coefficient increases under forward directivity pulses and decreases under flin-step pulses.Furthermore,the peak horizontal acceleration at the bottom of slope induced by fling-step ground motions is larger than that of forward directivity or non-pulse ground motions.更多还原