拱坝横缝键槽形式对拱坝地震响应的影响分析  

Effects of contraction joints and key slots on the seismic responses of arch dam

作　　者：杜成斌[1] 江守燕[1] 

机构地区：[1]河海大学力学与材料实验中心,南京210098

出　　处：《水力发电学报》2010年第5期1-5,21,共6页Journal of Hydroelectric Engineering

基　　金：国家重点基础研究发展计划(973计划)(2007CB714104);中国水利水电科学研究院开放研究资金(2008538613)

摘　　要：建立了包含拱坝横缝键槽物理构造的简化矩形键槽和梯形键槽模型,横缝键槽接触面之间的本构关系采用指数型动接触本构模型,比较分析了平缝模型、矩形键槽模型以及梯形键槽模型对拱坝横缝局部以及拱坝整体应力-位移地震响应的影响。分析结果表明:与平缝模型相比,键槽的存在对拱坝横缝局部以及大坝整体的响应均有较大影响,横缝的开度明显增大,坝段之间的滑移量减小,横缝底端的应力集中现象明显减弱,上游坝面整体的应力状态有所改善,坝顶的最大顺河向位移有所降低;两种键槽模型对大坝整体的应力-位移响应的影响较接近,但对拱坝横缝局部的开度及坝段之间的滑移量影响较大。A simple numerical model for rectangular shear keys and trapezoidal shear keys are presented,and the exponential nonlinear dynamic contact models are adopted to simulate the contact relations of joint profiles.The effects of plane joints,rectangular shear keys and trapezoidal shear keys on the local responses of contraction joints and the global responses of stress and displacement of arch dam are compared.It is shown that the shear keys have greater effects on both the local and global responses.The keys cause an increase in the joint opening while a decrease in the slide along joints,and they cause a considerable reduction in the stress concentration at the bottom of contraction joints and in the maximum stream-wise displacement of the dam crest.It is also found that the difference between rectangular and trapezoidal keys is not obvious in improving the global responses,but significant in the effects on the joint opening and slide along joints.

关 键 词：水工结构 地震响应 动接触本构模型 拱坝横缝 键槽 

分 类 号：TV642.44[水利工程—水利水电工程]