地震动力作用触发的斜坡崩滑高差效应研究

Study on difference in elevation response of slope collapsing and sliding triggered by seismic action

运用岩石动三轴剪切试验及有限差分数值试验技术,对地震动力作用触发的斜坡崩滑破坏时的坡体力学特征值空间变化规律进行了研究。研究表明:(1)地震动力作用触发的斜坡体崩滑破坏具有显著的"高差"效应,即斜坡体先期崩滑破坏大多起始于坡肩部位;(2)斜坡体临界破坏应变有随坡体微元埋深减小而减小的趋势,临界破坏应变小和坡肩地震峰值加速度的优势放大双重因素导致坡肩部位优先发生先期破坏;(3)斜坡体动态抗剪强度有随坡体微元埋深减小而减小的趋势,临界动态抗剪强度低和坡肩地震峰值加速度的优势放大双重因素导致坡肩部位优先发生先期破坏。

Spatial distribution of slope mechanical parameters on its collapsing and sliding triggered by seismic load is studied by applying rock dynamic triaxial shear test and finite difference numerical simulation.Results show that evident difference in elevation response of slope initial collapsing and sliding triggered by seismic dynamic influence,i.e.initial fracturing always originates in the place of slope shoulder.Secondly,critical failure strain decreases with buried depth decreasing of slope body unit,and double factors that critical failure strain decreasing and peak ground acceleration increasing in slope shoulder result in initial fracturing here.Thirdly,dynamic shear strength decreases with buried depth decreasing of slope body unit,and double factors that dynamic shear strength decreasing and peak ground acceleration increasing in slope shoulder lead to initial fracturing here.The above results contribute to revealing key controlling factors and dynamic process of slope collapsing and sliding triggered by seismic load and providing reference for further relative study.