弱震情况下高土石坝坝料动力参数反演分析  

Back analysis of dynamic parameters of high earth-rock dam materials under weak earthquakes

作　　者：王茂华 迟世春 相彪 周雄雄 WANG Mao-hua;CHI Shi-chun;XIANG Biao;ZHOU Xiong-xiong(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China;Institute of Earthquake Engineering,School of Hydraulic Engineering,Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China;College of Water Resources and Hydraulic,Yunnan Agricultural University,Kunming 650201,China)

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024 [2]大连理工大学建设工程学部水利工程学院工程抗震研究所,辽宁大连116024 [3]云南农业大学水利学院,云南昆明650201

出　　处：《岩土工程学报》2020年第2期289-298,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家重点研发计划项目(2016YFB0201001)。

摘　　要：通过传递函数结合黏弹性人工边界模型实现了三维河谷地形下地震动的输入问题,不仅考虑了坝基相互作用和地基辐射阻尼的影响,而且较好地考虑了河谷地形的影响,保证了大坝动力计算的地震动输入的合理性。然后利用多输出支持向量机代替有限元计算,需要的样本数量相对较小,并且避免了传统单一支持向量机容易忽略监测数据间的相关性的问题,精度满足计算的要求,最后利用粒子群优化算法对反演参数进行优化选择。对糯扎渡心墙堆石坝动力参数的反演结果表明,测点加速度与实测值吻合较好。说明提出的方法是可行的,适用于弱震情况,可以为缺乏强震或震害资料的坝体动参数反演提供依据。最大动剪切模量系数C值与三轴试验方法和缩尺效应等有关,反演得到的堆石料最大剪切模量系数C值比室内动三轴试验值偏大,可以为室内试验值修正提供参考;并且由于受到上游蓄水的原因,反演得到上游堆石料最大动剪模量系数C值又比下游堆石料小40%左右,工程应用时室内试验值建议予以适当的修正。In the case of weak earthquakes,a back analysis model considering interaction and radiation damping effects is proposed for dynamic parameters of earth-rock dams.In the model,the viscous-elastic artificial boundary combined with transfer function is used for achieving the wave motion input of valley topography,and the multiple output support vector machine(MSVM)and particle swarm optimization(PSO)are adopted.Using PSO to optimize the dynamic parameters of the dam can effectively get the optimal combination of parameters.The trained MSVM used to describe the mapping relationship between the model parameters and the acceleration reduces computing time of parametric inversion,avoiding the problem that the traditional single support vector machines easily ignore the correlation between monitoring data.The inversion results of Nuzhadu dam show that the calculated settlements agree well with the measured data.The proposed model is feasible in back-analysis of dynamic parameters of earth-rock dams.The study shows that the dynamic shear modulus coefficient C of the dam materials obtained from the indoor dynamic triaxial tests is small and should be revised.

关 键 词：弱震 动力参数 反演 黏弹性边界 传递函数 多输出支持向量机 粒子群算法 

分 类 号：TU435[建筑科学—岩土工程]