海底地震动的等延性强度折减系数谱  

Strength reduction factor spectra with constant ductility for offshore ground motions

作　　者：陈宝魁[1] 李宏男[1] 王东升[2] 孙治国[2] 

机构地区：[1]大连理工大学建设工程学部,辽宁大连116024 [2]大连海事大学道路与桥梁工程研究所,辽宁大连116026

出　　处：《地震工程与工程振动》2014年第2期1-11,共11页Earthquake Engineering and Engineering Dynamics

基　　金：国家重点基础研究发展计划(973项目)(2011CB013605);国家自然科学基金项目(51178071;51008041);教育部新世纪优秀人才支持计划资助项目(NCET-12-0751);辽宁省高等学校优秀人才支持计划(LJQ2013053)

摘　　要：为了解海底与陆地地震动弹塑性地震反应谱的差别,本文选取日本K-NET强震台网近年收集的部分海底及陆地强震记录,总计6个海底台站与相邻8个陆地台站在6次地震中的67组(双向水平)强震记录,以统计分析的方法研究了海底台站及其相邻的陆地台站强震记录的等延性强度折减系数谱的特性。进一步选取美国"海底地震动观测系统项目(SEMS)"的7个台站在8次地震中的9组(双向水平)海底强震记录与K-NET海底强震记录的等延性强度折减系数谱进行了对比,以探求震中距、水深等对海底地震动等延性系数强度折减系数谱的影响。总体上看,海底与陆地地震动的等延性强度折减系数谱相差不大,震中距对海底地震动等延性强度折减系数谱有一定影响,特别在周期T<1.5 s时,震中距越大其谱值越小,而水深对其影响不大。In order to study the differences in inelastic response spectra between offshore and onshore ground mo- tions, the characteristic of the strength reduction factor spectra with constant ductility for offshore ground motions and their adjacent onshore ground motions were statistically analyzed. 67 ground motion records with two horizontal components at 6 offshore and 8 adjacent onshore stations in 6 earthquake events were selected from Japanese K-NET strong-motion network in recent years. Further, 9 offshore ground motion records with two horizontal components at 7 offshore stations in 8 earthquake events were selected from the SEMS in the USA, and the strength reduction fac- tor spectra with constant ductility for offshore ground motions from the K-NET were compared with the offshore ground motions from the SEMS. The influences of epicentral distance and water depth on the spectra were also dis- cussed. In general, the differences in strength reduction factor spectra between offshore and onshore ground motions are little. The epicentral distance has some influence on the strength reduction factor spectra for offshore ground motions, especially for periods less than 1.5 s, the larger the epicentral distance, the lower spectral value will be. It is found that the water depth has little effect on the spectra for offshore ground motions.

关 键 词：海底地震动 弹塑性反应谱 强度折减系数 K—NET强震台网 震中距 水深 

分 类 号：P315.63[天文地球—地震学] P315.9[天文地球—固体地球物理学]