地震作用下边坡平台对边坡的动力响应及失稳破坏影响分析  

Effect of Platform on Dynamic Response and Failure Mechanism of Soil Slope under Earthquake Action

作　　者：黄诗渊[1] 刘健[1,2] 李书杰 邓增凯 熊磊[1] 文俊 

机构地区：[1]重庆交通大学河海学院,重庆400074 [2]重庆市水利电力建筑勘测设计研究院,重庆401121 [3]赣州市水文局,江西赣州341000

出　　处：《长江科学院院报》2015年第7期70-76,共7页Journal of Changjiang River Scientific Research Institute

摘　　要：利用有限元分析软件建立数值计算模型,采用基线校正的10 s水平加速度时程作为地震输入条件,对在不同平台个数、平台宽度以及平台分布等多种工况下边坡模型的动力响应及稳定性进行数值模拟分析。结合各工况地震过程中坡面质点PGD放大系数、动剪应力峰值与震后最大剪应变、塑性区范围以及稳定性评价指标,对地震作用下边坡动力响应特性和失稳破坏进行了定性的评价研究。计算结果表明：以本文40 m高的边坡为例,设单个平台时,于15 m和20 m高程处设置平台对边坡动力稳定性更有利;设2个平台时,10-20 m的平台组合相对于其它组合对边坡动力稳定性更有利;对于多级边坡,随着平台宽度的增加,边坡整体破坏趋势逐渐分解为各级边坡局部破坏趋势,可以较大幅度地减小最下方坡脚的应力集中,进而提高边坡的动力稳定性;此外,平台内侧属于上级边坡的坡脚处,易产生剪应力集中区,属于薄弱部位,应加强各级坡脚的支护。A numerical model was established by using finite element software to simulate the dynamic response and stability of slope.In the simulation,a baseline-corrected 10s horizontal acceleration was set as earthquake input, and the platform amount,platform width and platform distribution were set different.Furthermore,according to the particle PGD amplification coefficients,peak dynamic shear stresses,maximum shear strains after earthquake, plastic zones and stability indexes of slope in different conditions during the earthquake,the dynamic response and stability of slope were quantitatively assessed.Results suggest that：for slopes of 40m high in the present paper, single platform set at 15m and 20m is beneficial to the slope’s dynamic stability;while in the case of setting double platforms,platform position at 10m -20m of the slope could better restrain the instability than other positions;for slopes of multiple levels,with the increase of platform width,the global failure trend gradually degenerates into lo-cal failure,which could greatly reduce the stress concentration at the slope toe;in addition,shear stress is prone to concentrate at the inner side of platform,so the slope toes should be strengthened at all levels.

关 键 词：地震 均质土坡 动力响应 平台 剪应变 塑性区 稳定性评价指标 

分 类 号：TU435[建筑科学—岩土工程]