地震荷载作用下危岩体边坡动力响应及失稳机理探讨  

NUMERICAL INVESTIGATION OF DYNAMIC RESPONSE AND INSTABILITY MECHANISM FOR DANGEROUS ROCK MASS SLOPE UNDER EARTHQUAKE LOADS

作　　者：刘明星[1] 刘恩龙[1] 张世殊[1] 张建海[1] 

机构地区：[1]四川大学水力学与山区河流开发保护国家重点实验室、水利水电工程学院,成都610065

出　　处：《工程地质学报》2016年第2期187-196,共10页Journal of Engineering Geology

基　　金：国家自然科学基金项目(51009103)资助

摘　　要：采用连续介质快速拉格朗日分析方法,模拟了含单一顺坡向结构面的危岩体边坡在地震荷载作用下的动力反应。基于时程分析法,分析了其动力响应规律,并简单探讨了失稳机理。发现了危岩体边坡的加速度和速度存在竖直放大效应和临空面放大效应。受结构面的影响,加速度、速度、位移和剪应力等的不连续现象明显,危岩体边坡的水平位移峰值在结构面以下向上逐渐减小、跨过结构面时突然增大、在结构面以上又向上逐渐减小,而危岩体上的位移放大系数明显比母岩上的大。有助于进一步研究结构面的动力特性和危岩体边坡的动力失稳机理。The paper models the dynamic response for dangerous rock mass slope with a bedding structural plane under earthquake loads using the fast lagrangian analysis of continua.Based on time-history analysis method,the law of dynamic response is analyzed and its instability mechanism is also investigated.The results show that there are vertical and free surface amplification effects in the distribution of horizontal acceleration and velocity within the dangerous rock mass slope.The results are obviously influenced by the structural plane,discontinuous phenomena of acceleration,velocity,displacement and shear stress.Its peak horizontal displacements reduce gradually upward when it is below the structural plane,increase suddenly when across the structural plane and continue to reduce gradually upward when above it.Obviously,the amplification factor for horizontal displacement in the dangerous rock mass is larger than that in the mother rock mass.It is conducive to the further study the dynamic characteristics of the structural plane and dynamic instability mechanism for dangerous rock mass slope.

关 键 词：危岩体 地震荷载 数值模拟 动力响应 

分 类 号：TU45[建筑科学—岩土工程]