陡倾层状岩质边坡动力响应大型振动台模型试验研究  

LARGE-SCALE SHAKING TABLE MODEL TESTS FOR DYNAMIC RESPONSE OF STEEP STRATIFIED ROCK SLOPES

作　　者：李振生[1] 巨能攀[1] 侯伟龙[1] 李果[1] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《工程地质学报》2012年第2期242-248,共7页Journal of Engineering Geology

基　　金：教育部重点项目支持(2011156);"十二五"国家科技支撑计划(2011BAK12B03)资助

摘　　要：结合5.12汶川地震诱发的大量次生地质灾害,设计并完成了比例为1:100的边坡大型振动台模型试验,讨论了相似关系和模型的设计、传感器的布置、模型的建造过程,编制了动荷载加载制度。试验结果表明,边坡对输入动荷载具有放大作用,沿坡面向上,PGA放大系数呈上升趋势,并具有一定的节律性,其节律性变化规律受坡体岩性、结构面组合和动荷载振动方向的影响;动荷载X向振动时的坡面峰值重力加速度(PGA)放大系数明显大于Z向振动时的坡面PGA放大系数,说明坡体在X向振动时的动力响应更为强烈;坡体内PGA放大系数在铅直向上呈线性放大,在水平向上表现为节律性变化。试验结果有助于了解陡倾层状岩质边坡在不同动荷载作用下的响应规律,对研究其变形失稳机制和抗震结构设计提供了依据。This paper is based on a large number of secondary geological disasters induced by the Wenchuan Earthquake.It designs and completes a large-scale shaking table model test of slopes with the scale of 1： 100.It discusses the design of similarity relation and the model,sensor layout,process of model construction as well as the seismic wave loading system.The results show that the model slopes have amplification effect to the input dynamic load.Upward along with the slope surfaces,the PGA amplification coefficients have a rise tendency and some rhythmic.The variation law of rhythmic is affected by the lithology of slopes,combination of structural surface and vibration direction of the dynamic loads.Coefficients of the PGA amplification along surface of slopes are significantly greater for the vibration direction of dynamic load to horizontal（X）than for the direction of dynamic load to vertical（Z）,which shows that the dynamic response of slopes is stronger when the vibration direction X.The PGA amplification coefficients in the vertical direction of the slope body are amplified linearly.They in the horizontal direction change in rhythm.The results can help to understand the dynamic response rules of steep stratified rock slopes in the effect of different kinds of dynamic loads,and provide a basis to study the mechanism of deformation and instability of slopes under earthquake and the design of anti-earthquake structure.

关 键 词：岩质边坡 动力响应规律 振动台模型试验 PGA放大系数 

分 类 号：P642.22[天文地球—工程地质学]