基于强震记录的多维地震动降维建模  

Dimension-reduction simulation of multi-dimensional ground motions based on strong motion records

作　　者：刘章军[1,2] 姜云木 刘子心 岳庆霞 LIU Zhangjun;JIANG Yunmu;LIU Zixin;YUE Qingxia(College of Hydraulic&Environmental Engineering,China Three Gorges University,Yichang 443002,China;School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China;Key Laboratory of Building Collapse Mechanism and Disaster Prevention,Institute of Disaster Prevention,China Earthquake Administration,Sanhe 065201,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering,Ministry of Education,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002 [2]武汉工程大学土木工程与建筑学院,武汉430074 [3]防灾科技学院中国地震局建筑物破坏机理与防御重点实验室,河北三河065201 [4]山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室,济南250101

出　　处：《振动与冲击》2022年第18期244-251,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51978543,52108444,51778343);湖北省高等学校优秀中青年科技创新团队计划(T2020010);河北省自然科学基金(E2021512001);山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室开放基金(SYS00402)。

摘　　要：地震动具有多维性,如何合理建立多维地震动是复杂工程结构精细化抗震分析的基础。首先,以1 766组实测多维强震记录为依据,建议了一类多维地震动的迟滞相干函数模型;其次,研究地震动平动分量在幅值、持时及频谱之间的关系,建立了多维地震动的演变功率谱模型;最后,基于本征正交分解的随机向量过程降维方法,实现了仅用两个基本随机变量即可有效模拟多维地震动过程。数值算例表明,降维方法生成的多维地震动代表性时程具有良好效率,且平动分量的相干性、反应谱以及幅值谱均与实测记录拟合一致,验证了多维地震动降维模型的精确性和工程适用性。同时,采用降维方法生成的多维地震动代表性时程具有赋得概率,并构成一个完备的概率集,可与概率密度演化理论相结合,进而为复杂工程结构抗震可靠性精细化评价提供有效途径。Earthquake ground motion has multi-dimensional characteristic,of which the reasonable description is the basis for the refined seismic analysis of complex engineering structures.Firstly,based on 1 766 groups of measured multi-dimensional strong motion records,a kind of lagged coherence function model of multi-dimensional ground motions was proposed.Then,the relationship among the amplitude,duration and spectrum of three-dimensional ground motion components was studied,and the evolutionary power spectrum model of multi-dimensional ground motions was established.Finally,by introducing the dimension-reduction method based on proper orthogonal decomposition for the random vector process,the simulation of multi-dimensional ground motions was realized using just two elementary random variables.Numerical examples show that the representative time histories of multi-dimensional ground motions generated by the dimension-reduction method are fairly efficient.The coherence,response spectrum and amplitude spectrum of the three-dimensional components are consistent with the measured records,which verifies the accuracy and engineering applicability of the dimension-reduction model.Meanwhile,the representative time histories are of assigned probability and can make up a complete probability set.The dimension-reduction method can be combined with the probability density evolution theory,providing an effective way for the refined seismic reliability evaluation of complex engineering structures.

关 键 词：多维地震动 实测强震记录 相干函数 演变功率谱 降维模拟 

分 类 号：P315.9[天文地球—地震学]