海底地震动特性及相关谱研究  

Study on the Characteristics of Offshore Ground Motion and Its Response Spectra

作　　者：陈宝魁[1] 王东升[2] 李宏男[1] 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：《防灾减灾工程学报》2016年第1期38-43,共6页Journal of Disaster Prevention and Mitigation Engineering

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项目(NCET-12-0751);辽宁省高等学校优秀人才支持计划项目(LJQ2013053);中央高校基本科研业务费项目(3132015225)资助

摘　　要：利用日本K-NET与美国SEMS台网中海底强震记录研究了海底地震动特性。通过分析水平反应谱、竖向与水平加速度反应谱的比谱和弹塑性反应谱,比较了海底与陆地地震动的区别。发现海底竖向地震动的峰值加速度明显更低。在大于0.2s的周期段,海底水平地震动反应谱大于陆地谱值,而且海底谱具有更长的特征周期,并随震中距增长而增大。此外,海底地震动的竖向与水平加速度反应比谱与陆地地震动的差异很大,在小于1s的中短周期段海底地震动的比谱明显更小。根据不同的震级与震中距的真实地震动记录,提出了中等地震下不同震中距海底地震动比谱的简化设计方程。最后,比较了海底与陆地地震动的弹塑性反应谱,可知总体上海底与陆地的等延性强度折减系数谱差异不大。The characteristics of offshore ground motions were studied on the basis of the records from the Kyoshin network（K-NET）in Japan and Seafloor Earthquake Measuring System（SEMS）in the USA.The horizontal response spectra,the vertical-to-horizontal response spectral ratios（V/H RS ratios）,and the inelastic response spectra were analyzed to compare the differences in offshore and onshore ground motions.It is found that the PGA of vertical components for offshore ground motions is lower.The horizontal response spectral values for offshore ground motions are higher for periods longer than 0.2s.The characteristic periods of offshore ground motions is longer than that of onshore ground motions,the larger the epicentral distance,the longer the characteristic period will be.Moreover,it is very different in the V/H RS ratios between offshore and onshore ground motions.The V/H RS ratios for offshore ground motions are obviously higher than that for onshore ground motions at short to middle periods lower than1 s.Further more,the simple design equations of V/H RS ratios for offshore ground motions are derived on the basis of the real ground motion recordings with different earthquake magnitudes and epicentral distances.At last,to compare the inelastic response spectra,the difference in strength reduction factor spectra between offshore and onshore ground motions is slight in general.

关 键 词：海底地震动 弹性反应谱 竖向与水平加速度反应比谱 等延性强度折减系数谱 

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]