不同地下水位碎石土斜坡对震动的差异性动力响应

摘要

基于室内小型振动台试验研究不同地下水位碎石土斜坡动力响应规律及变形破坏特征,对边坡的工程抗震设计有参考作用.结果表明,地下水具有一定的减震作用.有地下水边坡中下部的水平及竖直加速度峰值表现出局部高程减弱的趋势,边坡上部的水平及竖直向加速度峰值表现出高程放大的趋势.输入相同振动强度条件下,随着地下水位的增加,动力响应减弱区域增大,减震能力增强;地下水位越高,边坡顶部加速度放大系数越小.无地下水斜坡变形破坏主要发生在坡顶;有地下水斜坡变形破坏主要发生在坡脚.地下水位及振动强度的增加,加剧坡脚破坏的程度.%Based on the laboratory small-scale shaking table test,the dynamic response laws,deformation and failure characteristics of gravelly soil slopes at different groundwater levels were studied,which can be used as references for the seismic design of slopes.Tests revealed that the groundwater contained in slope served vibration absorption.The horizontal and vertical accelerations of the middle and lower parts of the slope with groundwater showed a tendency of decreasing with height downward,whereas in the upper part of the slope it presented an upward trend.Under the condition of the same vibration intensity,with the ascent of groundwater level,the weak zone of dynamic response increased and the shock absorption capacity increased.The higher the groundwater level,the smaller the acceleration amplification coefficient was found at the top of the slope.No groundwater slope occurred deformation and failure mainly in the top of the slope;Deformation in the groundwater slope took place and come to failure mainly in the slope foot.The increase of groundwater level and vibration strength aggravated the degree of foot damage.