近断层速度脉冲地震动引起的边坡永久位移预测模型

基于小波分析方法，从NGA数据库的3 551条地震记录中选取189条速度脉冲地震动，地震动均转换成发生最强脉冲的方向。基于Newmark方法，分析了近断层速度脉冲地震动作用引起的边坡永久位移值。结果表明：近断层速度脉冲地震动对边坡产生特殊的破坏作用，表现在滑动位移值大、滑动体破坏力强等方面；边坡永久位移值与速度脉冲地震动的峰值速度具有高度相关性，位移值较大时尤为明显。建立了基于单变量形式的峰值速度及双变量形式的峰值速度、峰值加速度两种边坡永久位移预测模型，模型简单实用，与回归数据具有很好的相关性，前者更适用于预测对实际工程影响较大的永久位移值，且离散性较小。提出的预测模型为考虑近断层地震动速度脉冲特性影响的边坡永久位移值的概率地震灾害分析提供了基础。

Predictive models for permanent displacement of slopes induced by near-fault pulse-like ground motions

189 ground motions from 3 551 recordings in the next generation attenuation (NGA) database are classified as pulse-like ground motions based on wavelet analysis; and all ground motions are rotated to orientations of the strongest observed pulse. Newmark method is used to calculate the permanent displacement of slopes induced by near-fault pulse-like ground motions; and the effects of velocity pulse-like characteristics on the slope permanent displacements are studied. The analyses indicate that the near-fault pulse-like ground motion has a significant effect on the damage of slopes, resulting in strong potential damage of permanent block and larger permanent displacement. It is shown that permanent displacement has a close relationship with the peak ground velocity; especially for the case of relatively large displacement. Two empirical predictive models for permanent displacements are developed by using the scalar intensity measure of peak ground velocity and vector intensity measures of peak ground velocity and peak ground acceleration. The scalar predictive model has small standard deviation when the permanent displacement is relatively large. The developed displacement predictive models can be used in probabilistic seismic hazard analysis for permanent displacement including the effects of near-fault pulse-like characteristics.