考虑材料参数空间变异性的沥青混凝土心墙坝‑覆盖层系统地震响应研究  

Research on seismic response of asphalt concrete core dam-overburden considering the spatial variability of material parameters

作　　者：王宗凯 宋志强[1] 刘云贺[1] 王飞[1] WANG Zong-kai;SONG Zhi-qiang;LIU Yun-he;WANG Fei(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi′an University of Technology,Xi′an 710048,China)

机构地区：[1]西安理工大学省部共建西北旱区生态水利国家重点实验室,陕西西安710048

出　　处：《振动工程学报》2022年第5期1188-1199,共12页Journal of Vibration Engineering

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(51479165,51779208);陕西省自然科学基础研究计划面上项目(2022JM‐276);陕西省教育厅青年创新团队科研计划项目(22JP052)。

摘　　要：覆盖层及坝体材料参数的空间变异性往往显著影响沥青混凝土心墙坝‐覆盖层系统的地震响应。提出一种基于数论选点的空间随机场模拟技术,通过数论选点方法实现随机点集分布优化,采用正态或对数正态分布函数考虑材料参数空间变异性,采用高斯型自相关函数考虑材料参数空间相关性,通过协方差分解生成随机参数库,实现了基于蒙特卡洛法的考虑坝体‐覆盖层材料空间差异性及相关性的随机场模拟和“非侵入式”随机有限元计算。以某实际工程为例,选取静力邓肯‐张E‐B本构模型和动力等效线性黏弹性本构模型中的敏感参数作为随机参数,分析了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;分析了输入地震动对随机响应离散程度和相对于确定值超越概率的影响。结果表明:数论选点法可以显著优化随机点集分布和提升计算效率;考虑材料参数的空间随机性会大概率引起坝体地震响应增大;坝体和覆盖层材料的空间差异性对坝顶和心墙顶水平峰值加速度的影响大于对永久变形的影响;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;忽略材料参数的空间变异性会造成沥青混凝土心墙坝‐覆盖层系统不同工况不同指标地震响应50%~90%概率的低估;覆盖层地震响应结果的离散程度大于坝体及心墙。The spatial variability of overburden and dam material parameters significantly affects the seismic response of asphalt concrete core dam-overburden system.This paper proposes a space random field simulation technology based on number theory se‐lection,and the random point sets distribution optimization is realized by using number theory selection method.The spatial correla‐tions of material parameters and the spatial variability of material parameters are considered using normal or lognormal distribution and Gaussian autocorrelation relationship,respectively.Random parameter library is generated by covariance decomposition in Py‐thon,and secondary script development is carried out for Abaqus finite element software.Based on the Monte Carlo method,the random field simulation and"non-invasive"random finite element calculation considering the spatial difference and correlation of dam-overburden material are realized.Taking an actual project as an example,the sensitive parameters in the static Duncan‐Chang E-B constitutive model and the dynamic equivalent linear viscoelastic constitutive model are regarded as random parameters.The statistical law and probability distribution tests of the mean value,variation coefficient and 95%confidence interval limit value of the horizontal peak acceleration of the asphalt concrete core dam and the vertical permanent deformation of the dam are analyzed.The influence of ground motion intensity on discrete degree of random response and transcendence probability relative to determi‐nate value is also analyzed.The result shows that the point selection method through number theory can significantly optimize the random point set distribution and improve computational efficiency.The randomness of material parameters will cause the seismic response of the dam to increase with a high probability,and the spatial difference of dam body and overburden materials has a great‐er impact on the peak horizontal acceleration of the top of the dam and core wall than on the permanent defor

关 键 词：沥青混凝土心墙坝 地震响应 覆盖层 空间变异性 随机有限元 

分 类 号：TV312[水利工程—水工结构工程]