耦合地震作用下多台阶岩质边坡动力响应分析

Dynamic Response Analysis of Multi-step Rock Slope under Coupled Earthquake

运用大型有限元软件ADINA对某重力坝库岸边坡,在场地波地震作用下,模拟单向地震无锚杆支护、单向地震有锚杆支护、耦合地震无锚杆支护及耦合地震有锚杆支护4种工况,从加速度、位移、应力、锚杆轴力及抗滑稳定安全系数几方面进行了动力响应分析。结果表明:锚杆在一定范围内对潜在滑移岩体有很好的嵌固作用,并能有效抑制边坡岩体对加速度的放大效应;多台阶边坡各台阶面和剪出点会产生局部拉应力,锚杆支护后可有效削减;对比单向地震,耦合地震作用下的边坡更危险,在边坡动力分析中应计入竖向地震的作用。研究结果可为同类工程抗震设计提供参考。

By using large-scale finite element software ADINA,the dynamic response of the bank slope of a gravity dam was analyzed from several aspects such as acceleration,displacement,stress,axial force of anchor bolt and anti-slide stability safety coefficient.The study simulated four operating conditions,including unidirectional earthquake without anchor blot support,unidirectional earthquake with anchor blot support,coupled earthquake without anchor blot support and coupled earthquake with anchor blot support.The results indicated that the anchor blot had great restrained action on potential sliding rock mass within a certain range and could effectively suppress the amplification effect on seismic acceleration caused by the rock slope.Every step surface and shear point of the multi-step rock slope was able to generate local tensile stress which could be reduced by anchor blot.The slope was more dangerous under coupled earthquake than unidirectional earthquake.So the effect of vertical earthquake should be considered in dynamic stability analysis of slope.The results can provide reference to similar engineering seismic design.