地基与库水模型对重力坝地震响应的影响研究  

Influence of foundation and reservoir water models on seismic responses of the gravity dams

作　　者：潘子悦 陈灯红[1,2] 赵艺园 刘云辉 PAN Ziyue;CHEN Denghong;ZHAO Yiyuan;LIU Yunhui(Hubei Key Laboratory of Disaster Prevention and Mitigation,China Three Gorges University,Yichang 443002,China;College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,China)

机构地区：[1]防灾减灾湖北省重点实验室(三峡大学),湖北宜昌443002 [2]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《灾害与防治工程》2021年第2期1-14,共14页Disaster and Control Engineering

基　　金：国家自然科学基金项目(52079072);土木工程防灾减灾湖北省引智创新示范基地(2021EJD026)。

摘　　要：本文采用有限元法构建了一种较为综合的重力坝-地基-库水系统地震响应分析模型,其中,采用黏弹性边界模拟无限坝基,采用等效荷载法实现地震动输入;采用声学单元及无反射边界条件楔拟坝-库动力相互作用。以第十五届国际大坝数值分析标准算例研讨会主题A中的Pme Flat重力坝为例研究了该模型的计算精度。以黄登混凝土重力坝12#挡水坝段为分析对象,考虑不同地基尺寸、地基辐射阻尼和库水可压缩性这些因素,分析该重力坝-地基-库水系统地震响应的变化规律。通过与无质量地基及附加质量模型的分析结果进行对比,结果表明:在无质量地基模型中,地基尺寸对大坝加速度响应有较大影响,坝顶加速度在2倍坝高时达到最大;当地基范围扩大时,坝踵点与坝顶点的水平相对位移峰值呈现递增规律,坝体的主拉应力峰值呈现递减趋势。与无质量地基模型的结果相比,考虑辐射阻尼效应模型的坝顶和坝踵的加速度峰值下降了6%-63%,相对位移峰值降低了50%左右,坝体主拉应力峰值降低了50%-60%,主压应力峰值降低了30%-40%。与附加质量模型的结果相比,流固耦合楔型在动水压力以及坝踵点与坝顶点的相对位移均有不同程度的降低,水平相对位移峰值减小了13.8%,坝体应力峰值降低幅度大约30%。A comprehensive seismic response analysis model of the gravity dam-foundation-reservoir system is constructed based on the finite element method in this paper,in which,the viscous-spring boundary is used to simulate the infinite dam foundation,and the equivalent load method is used to realize the ground motion input,the non-reflecting boundary condition is employed to simulate the dynamic interaction between the dam and the reservoir.Taking the 15th International Benchmark Workshop on Numerical Analysis of Dams Theme A-Seismic Analysis of Pine Flat Concrete Dam as an example,the calculation accuracy of the proposed model is studied.Taking the 12th retaining dam section of Huangdeng concrete gravity dam as an object,the seismic responses of the gravity dam-foundation-reservoir system is analyzed by changing the size of the foundation,considering the factors such as foundation radiation damping and reservoir water compressibility.Compared with the analysis results of massless foundation and added mass models,the results show that the foundation size has a significant influence on the dam acceleration response in the massless foundation model.The acceleration of the dam crest reaches the maximum at 2 times the height of the dam.When the local foundation size is extended,the peak value of the horizontal relative displacement between the dam heel and the crest shows an increasing law.The maximum principal tensile stress of the dam body shows a decreasing trend.Compared with the results of the massless foundation model,the peak accelerations at the crest and heel of the dam considering the radiation damping effect are reduced by 6%-63%,the horizontal relative displacement are decreased by about 50%,the maximum principal tensile stress of the dam is reduced by 50%-60%and the peak principal compressive stress is reduced by 30-40%.Compared with the results of the added mass model,the hydrodynamic pressure and the relative displacement between the heel and the crest of the dam have been decreased in different degrees in th

关 键 词：混凝土重力坝 黏弹性边界 流固耦合模型 地震响应 

分 类 号：TV6[水利工程—水利水电工程]