覆水峡谷-丘陵复合地貌的地震差动相干函数模型及规律特征与影响  

A coherence function model for simulating multi-support seismic motions of canyon-hill composite topography and characteristics

作　　者：陈欣宇 柳国环[1,2] 费琦翔 CHEN Xinyu;LIU Guohuan;FEI Qixiang(State Key Laboratory of Intelligent Construction and Operation in Hydraulic Engineering,Tianjin University,300350 Tianjin,China;School of Civil Engineering,Tianjin University,300350 Tianjin,China)

机构地区：[1]天津大学水利工程智能建设与运维全国重点实验室,天津300350 [2]天津大学建筑工程学院,天津300350

出　　处：《应用力学学报》2024年第2期392-403,共12页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.51978461)。

摘　　要：构建了覆水峡谷-丘陵复合地貌的地震差动模拟所需的相干函数模型。首先,提出并推导得到了考虑土体滤波效应和竖向距离的覆水峡谷-丘陵复合地貌相干函数模型表达式;探讨并阐述了相干性变化的规律特征及其物理本质。然后,基于新相干模型和传递函数构建地下功率谱矩阵,生成地下多点地震动;通过功率谱及相干函数拟合验证了模拟结果的科学性与合理性;对比分析了本研究提出的相干函数模型对多点地震动空间变异性的影响。最后,以一座连续刚构桥为例,探讨了新相干函数模型对结构地震差动响应的影响。结果表明:基于新相干函数模型的多点地震动相干性降低,各点地震动的空间变异性增大,进而加剧了结构各支承点运动的不同步性,最终导致结构地震差动响应增大。This paper innovatively provides a coherence function model,specially adapted for water-covered canyon-hill composite topography and for simulating the multi-support seismic motions.First,a new coherence function model considering the soil filtering effect and vertical distance is proposed and derived.The characteristics of coherence and physical meaning of the proposed model are further investigated and summarized.Then,the multi-support underground seismic motions are generated by decomposing the underground power spectral density matrix,which is formed by combining the coherence function based on the derived model with the transfer function.Subsequently,the reasonability and rationality of the simulated results are verified by comparing the simulated power spectrum and the coherence function to the theoretical ones.Finally,the influence of the presented coherence function model on the differential effect of multi-support seismic motions and the dynamic response of a continuous rigid frame bridge is specially analyzed,respectively.The results show that the coherence among the simulated variable seismic motions is relatively reduced,but the variability of seismic motions at each foundation is increased,which leads to the enlargement of the structural responses.

关 键 词：峡谷-丘陵复合地貌 相干函数 多点地震动 地震响应 

分 类 号：TU311.3[建筑科学—结构工程]