考虑覆盖层地基材料空间变异性的沥青混凝土心墙坝地震响应研究  

Seismic responses of an asphalt concrete core wall dam considering the spatial variability of overlay foundation materials

作　　者：罗博华 宋志强[1] 王飞 刘琛[2] 刘云贺[1] LUO Bohua;SONG Zhiqiang;WANG Fei;LIU Chen;LIU Yunhe(Institute of Water Resources and Hydro-Electric Engineering,Xi’an University of Technology,Xi’an 710048,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi’an 710043,China)

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《振动与冲击》2022年第2期53-63,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目(52039008);国家自然科学基金面上项目(51479165);陕西省创新人才推进计划青年科技新星项目(2017KJXX-64)。

摘　　要：河床覆盖土层参数不确定性往往显著影响其上覆沥青混凝土心墙坝的地震响应。将空间随机场模拟技术与有限元方法相结合,根据动力等效线性模型参数敏感性分析结果选取动力随机参数,采用正态或对数正态分布函数考虑覆盖层材料参数的空间变异性,采用高斯型自相关函数考虑空间相关性,采用Python进行协方差分解法生成随机参数库,并对ABAQUS软件进行脚本二次开发,实现了基于蒙特卡罗法的覆盖层材料空间相关性及差异性的随机场模拟和"非侵入式"随机有限元的计算。以某实际工程为例,分别考虑覆盖层材料静力参数随机、动力参数随机和静动力参数均随机进行分析,分析沥青混凝土心墙坝坝顶、心墙顶水平向峰值加速度和坝体竖向永久变形的均值、变异系数及95%的置信区间限值等统计规律及概率分布检验。结果表明:考虑覆盖层材料参数的随机大概率会引起坝体地震响应增大;同时考虑静动力参数随机时的地震响应与确定值相差最大;坝体的地震响应统计结果不一定符合正态或对数正态分布;考虑覆盖层材料空间差异性对峰值加速度的影响大于对永久变形的影响;覆盖层地震响应结果的离散程度大于坝体及心墙。The uncertainty of the parameters of the overburden soil layer often significantly affects the seismic responses of a dam with asphalt concrete core.The spatial random field simulation technology was combinedly used with the finite element method,a according to the sensitivity analysis results of a dynamic equivalent linear model,dynamic random parameters were selected,the spatial variability of covering material parameters was considered by using normal or lognormal distribution functions,the Gaussian autocorrelation function was used to consider the spatial correlation,the random parameter library was generated by the covariance decomposition of Python,and the secondary development of scripts for ABAQUS was carried out.On these bases,by using the Monte Carlo method,the random field simulation of spatial correlation and discrepancy of covering materials and the“non-invasive”stochastic finite element analysis were realized.Taking a practical project as an example,the cases of random static parameters,random dynamic parameters and random static and dynamic parameters of overburden materials were considered respectively.The statistical analysis and probability distribution test for the mean value,coefficient of variation and 95%confidence interval limit of the horizontal peak acceleration at the asphalt concrete core dam crest and core crest and of the vertical permanent deformation of the dam body were conducted.The results show that:considering the random probability of overburden material parameters will increase the seismic response of the dam body;considering the random static and dynamic parameters,the difference between the seismic response and the determined value is the largest;the statistical results of seismic response of the dam body do not necessarily conform to normal or lognormal distribution;the influence of spatial discrepancy of overburden material on the peak acceleration is greater than that on the permanent deformation;the dispersion degree of seismic response results of the overburden laye

关 键 词：沥青混凝土心墙坝 随机有限元 覆盖层 空间变异性 地震响应 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3