地震动波动输入方法在高土石坝动力分析中的应用研究  

Application of Earthquake Wave Motion Input Method to High Earth-Rock Dam Dynamic Analysis

作　　者：魏匡民[1,2] 陈生水 李国英[1,2] 米占宽 沈婷[1,2] Wei Kuangmin;Chen Shengshui;Li Guoying;Mi Zhankuan;Shen Ting(Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China;Key Laboratory of Failure Mechanism & Safety Control Techniques of Earth-Rock Dam of Ministry of Water Resources,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院岩土工程研究所,南京210024 [2]水利部土石坝破坏机理与防控技术重点实验室,南京210029

出　　处：《三峡大学学报（自然科学版）》2019年第1期17-23,共7页Journal of China Three Gorges University：Natural Sciences

基　　金：国家重点研发计划重点专项(2017YFC0404904);水利部公益性行业专项经费项目(201501035);国家自然科学基金青年科学基金项目(51509163);中央级公益性科研院所基本科研业务费(Y317004)

摘　　要：地震动输入方法是高土石坝动力分析的重要方面,传统的一致性地震动输入方法难以合理反映地震波的"行波效应"和"地基辐射阻尼"现象,本文将地震动波动输入方法引入了土石坝有限元静动力分析程序TOSS3D,通过与解析解比较,验证了开发程序的正确性.以拟建新疆247m高大石峡砂砾石面板坝为依托工程,对比分析了一致性输入和非一致性地震动输入情况下大坝加速度反应、动位移、坝体残余变形以及防渗体动应力的差异.结果表明,波动输入方法由于考虑了地基的辐射阻尼现象,其计算所得的加速度放大系数、面板动应力以及坝体残余变形均较一致性输入小.研究认为,采用波动输入方法更有助于评估大坝的实际抗震能力,对于200～300m级高土石坝地震分析应采用能够反映土石坝坝体与基岩之间相互作用的数值模型.The ground motion input method is one of the most important aspects in dynamic analysis of high earth-rock dams.To simulate an earth-rock dam earthquake,the traditional uniform excitation method is easy to execute,however,it can not reasonably reflect the phenomenon of "traveling wave effect"and "radiation damping of infinite foundation".In this paper,the earthquake wave motion input method is incorporated into the TOSS3D FEM program.The earthquake wave motion input method can overcome shortcomings of the uniform excitation method;the "traveling wave effect"and "radiation damping of infinite foundation"can be both reflected.The FEM program is also verified by comparing with the analytical solutions using the free field wave propagation program.The 247 m high Dashixia dam in Xinjiang Autonomous Region of China is analyzed;the results of the acceleration response,dynamic displacement,residual deformation and dynamic stress of the slab are all compared with the uniform excitation method.It can be concluded that the results of the earthquake wave motion input method are smaller than that of the uniform excitation method in acceleration magnification factor,dynamic stress of the concrete slab and the residual deformation. Therefore,when adopting the earthquake wave motion input method,actual seismic capacity of the dam body can be predicted more accurate.For analyzing the high earth-rock dams of 200-300 m,the numerical model considering interaction between dam body and bedrock should be adopted.

关 键 词：高土石坝 地震 人工边界 大石峡坝 

分 类 号：TU45[建筑科学—岩土工程]