长周期结构远场地震强度调幅指标研究  

Research on amplitude modulation index of far-field earthquake intensity for long-period structures

作　　者：田英侠[1] 李思润 Tian Ying-xia;Li Si-run(School of Civil Engineering,Xi’an Technological University,Xi’an 710021,China)

机构地区：[1]西安工业大学建筑工程学院,陕西西安710021

出　　处：《工程抗震与加固改造》2022年第1期144-151,137,共9页Earthquake Resistant Engineering and Retrofitting

基　　金：陕西省重点研发计划(2019GY-079)。

摘　　要：针对远场地震采用峰值加速度(PGA)为强度指标不适用长周期结构的问题,本文选取了10条远场地震记录分析了其各类反应谱特性,并结合双线性单自由度(SDOF)体系在远场地震下的最大响应与12种强度指标的相关性研究,提出将峰值速度(PGV)作为表征长周期结构远场地震强度的参数,进一步分别采用PGA与PGV作为强度调幅的方式对一座长周期的斜拉桥进行时程响应分析。研究结果表明:以PGA为强度调幅指标时,远场及普通地震对长周期结构作用结果差异较大,其中位移响应尤为明显;而以PGV为强度调幅指标时,可克服地震动特性带来的影响差异,使两类地震对长周期结构作用结果离散性减小,故远场地震作用下长周期结构以PGV作为强度调幅指标更为合理。In view of the problem that the peak ground acceleration(PGA)is not suitable for long-period structures in far-field earthquakes,this paper proposes the peak ground velocity(PGV)as the strength parameter of far-field earthquakes based on analyzing the various response spectrum characteristics of 10 far-field seismic records selected and discussing the correlation of 12 strength indexes of the earthquakes with maximum responses of bilinear single degree of freedom system.And then,the time-history response analysis of a long-period cable-stayed bridge is carried out by using PGA and PGV as the seismic intensity amplitude modulation,respectively.The research shows that,the results of far-field and ordinary earthquakes on the long-period structure are quite different when taking the PGA as the intensity amplitude modulation index,especially for the displacement response.While,taking PGV as the intensity amplitude modulation index can reduce the discreteness of the results of the two types of earthquakes on the long-period structure,and overcome the difference of ground motion characteristics,so it is more reasonable to take PGV as strength amplitude modulation index for long period structure under far field earthquake.

关 键 词：远场地震动 峰值加速度 峰值速度 强度指标 长周期结构 

分 类 号：TU973[建筑科学—结构工程]