不同场地条件下远场地震动强度指标与结构最大响应的相关性分析  

Correlation Analysis between Intensity Measures of Far-Field Ground Motion and Maximum Structural Seismic Responses under Different Site Conditions

作　　者：梁逸文 陈清军[1] LIANG Yiwen;CHEN Qingjun(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《力学季刊》2022年第3期592-602,共11页Chinese Quarterly of Mechanics

基　　金：国家自然科学基金(51778489);国家科技支撑计划课题(2015BAK17B04);科技部国家重点实验室基础研究资助项目(SLDRCE19A-02)。

摘　　要：为探究不同场地条件下远场地震动强度指标与结构最大响应的相关性问题,本文从K-NET和KiK-net台网强震记录中选取震级7级以上、断层距大于200 km的地震动记录1328条,首先选用28个地震动强度指标进行了远场地震动强度指标与结构最大响应的总体相关性分析.然后,分别选取典型加速度类地震动强度指标、典型速度类地震动强度指标和典型位移类地震动强度指标进行了场地条件对结构最大响应相关性的影响分析.结果表明:(1)加速度类地震动强度指标的相关系数随单自由度(SDOF)体系周期增大逐渐减小,与自振周期结构T≤1 s的低自振周期结构响应具有明显的相关性;速度类地震动强度指标的相关系数在T=2~5 s具有较大值,说明这一类指标与中长周期结构的响应具有明显相关性;当T>3~5 s时,典型位移类地震动强度指标的相关系数逐渐增大进入峰值区段,并保持较大的相关系数值,因此可以采用这一类指标表征长周期结构响应.(2)对于加速度类地震动强度指标,Ⅰ、Ⅱ、Ⅲ类场地的相关系数随自振周期变化曲线走势较接近,Ⅳ类场地的相关系数值总体上要大于其它三类场地的相关系数.对于速度类地震动强度指标,在短周期区域,相关系数大小呈现Ⅰ<Ⅱ<Ⅲ<Ⅳ的特点;当T>2 s后,四类场地的相关系数随自振周期变化曲线趋势逐渐接近.对于位移类地震动强度指标,当T>3 s后,Ⅰ类场地和Ⅱ类场地的相关系数随自振周期变化曲线逐渐趋于一致,而Ⅲ类场地和Ⅳ类场地的相关系数随自振周期变化曲线也逐渐趋于一致.In order to investigate the correlation between the intensity measures related to far-field ground motion and the maximum structural seismic responses,a parametric statistical study based on 1328 far-field ground motion records was conducted.The records were selected from Japanese strong-motion seismograph networks(K-NET,KiK-net),following the principle that the magnitude is not lower than 7.0 and the fault distance is not lower than 200 km.28 corresponding intensity measures were first utilized to conduct the general analysis.Specific analysis based on typical acceleration-related,velocity-related and displacement-related measures was then respectively conducted to identify the influence of site condition on the correlation between the intensity measures and the maximum structural responses.The results indicate that the correlation coefficients of acceleration-related measure increase with the increase of the fundamental period(T)of the single degree of freedom(SDOF)system,demonstrating a distinct correlation with the structural responses of short period(T≤1 s)structure.The correlation coefficients of velocity-related measure possess a comparatively high value at the range of T=2-5 s,indicating a distinct correlation with the responses of the medium-to-long period structure.When T exceeds 3-5 s,the correlation coefficients of displacementrelated measure gradually increase and enter the high value range,demonstrating that they are capable of representing the seismic responses of long-period structure.In addition,for acceleration-related measures,the variations of period-correlation curves for site Ⅰ/Ⅱ/Ⅲ are similar,whereas the correlation coefficients of site Ⅳ possess a higher value than those of other sites.For a shorter period,the correlation coefficients of velocity-related measure for different site conditions are concluded to be Ⅰ<Ⅱ<Ⅲ<Ⅳ.For a longer period(T>2 s),the period-correlation curves for different sites tend to converge.For displacement-related measures,when T exceeds 3s,the curve

关 键 词：不同场地条件 远场地震动 强度指标 结构最大响应 相关性分析 

分 类 号：P315.9[天文地球—地震学]