汶川地震动弹性和弹塑性反应谱分析  

Elastic and elastoplastic response spectra of the Wenchuan earthquake ground motions

作　　者：王东升[1,2] 李晓莉[1,2] 孙治国[1,2] 陈宝魁[1,2] 石岩[1,2] 

机构地区：[1]大连海事大学道路与桥梁工程研究所,辽宁大连116026 [2]辽宁省公路工程重点试验室,辽宁大连116026

出　　处：《地震工程与工程振动》2013年第2期43-54,共12页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51178071;51008041;50878033);国家重点基础研究发展计划(973项目)(2011CB013605);教育部新世纪优秀人才支持计划资助项目(NCET-12-0751)

摘　　要：利用汶川地震获得的数字强震记录研究了汶川近场无速度脉冲、近场含速度脉冲和远场(盆地效应)地震动的弹性和弹塑性反应谱,后者包括等延性强度折减系数谱Rμ、等延性位移比谱Cu和等强度折减系数位移比谱CR。与相同场地条件PEER近场无速度脉冲、集集近场含速度脉冲地震动的谱进行了比较。汶川近场含速度脉冲地震动的弹性反应谱在0.2～0.8s周期内明显偏小,而它的弹塑性反应谱在短周期段(0.1～0.4 s)与汶川近场无速度脉冲地震动谱差别不大,但等延性强度折减系数谱Rμ要大于集集地震含速度脉冲地震动的谱,而等延性位移比谱Cu和等强度折减系数位移比谱CR则小于集集地震动情况,此后随周期增长(至0.6～1.0 s后)它们都逐渐过渡至与集集地震动的谱相当。汶川远场(盆地效应)地震动的弹性反应谱具有较宽并随周期缓慢增长的平台值和较长的特征周期,可达1.7s及以上。提出了远场(盆地效应)与近场地震动的弹性反应比谱和弹塑性位移比谱的概念。The elastic and the elastoplastic response spectra of the near field records without pulse-like wave, near- field records with pulse-like wave and far field records with basin effects were studied by statistic analysis method u- sing digital ground motion records in Wenchuan earthquake. The strength reduction factor spectra with constant ductility（ Ru ）, the displacement ratio spectra with constant ductility （Cu ）, and the displacement ratio spectra with constant strength reduction factor（ Cn） were included in the inelastic spectra of the Wenchuan earthquake records. By comparing with the response spectra of the PEER near field ground motions without pulse-like wave and the Chi- Chi ground motions with pulse-like wave on the same site, it can be drawn that the elastic response spectra of the Wenchuan near-field ground motions with pulse-like wave are obviously small in periods between 0.2 s and 0.8 s, and its elastoplastic spectra are almost the same with that of the Wenchuan near-field ground motions without pulse- like wave in periods between 0.1 s and 0.4 s, but the R~ spectrum is bigger and the displacement ratio Cu and Cn spectrum are smaller than that of the Chi-Chi ground motions. When the period is longer than 0. 6 ~ 1.0 s, all the inelastic spectra of the Wenchuan pulse-like wave ground motions are beginning to be equal to that of the Chi-Chiground motions. The platform of the elastic response spectra of the Wenchuan far field ground motions with basin effects is wide and the values are increasing with the periods gently, and the characteristic period of the spectra can reach to exceed 1.7s. The concept of elastic displacement response ratio spectra and elastoplastic displacement rati- o spectra between far-field ground motions with basin effects and near-field ~round motions are oronosed

关 键 词：汶川强震记录 弹性反应谱 弹塑性反应谱 近场 速度脉冲 盆地效应 

分 类 号：P315.9[天文地球—地震学] U443.21[天文地球—固体地球物理学]