【摘要】 跨海桥梁抗震时程分析通常采用陆地强震记录作为输入，因海底场地环境与陆地存在诸多差异，需对该方法进行深入研究。结合工程实际，利用ADINA软件建立基底固接跨海隔震连续梁桥分析模型。基于日本KiK-net台网选取震级及震中距相似的7个海底强震台站和7个近岸陆地强震台站各14条水平地震动（EW和NS方向独立考虑），沿桥梁纵桥向输入并进行地震反应时程分析，研究海底地震动和近岸陆地地震动输入下跨海隔震桥梁地震反应。通过对比桥墩最大变形及受力、主梁位移反应和支座最大剪应变，认为在大多数情况下，海底地震动作用下桥梁结构地震反应为近岸陆地地震动的1.3～1.9倍。跨海隔震桥梁抗震时程分析宜采用海底地震动作为输入。更多还原

【Abstract】 The strong earthquake records onshore usually are input as seismic time history analysis of cross-sea bridges. Because of the differences between the environment of the seabed and the land, this method needs to be studied carefully. Taking a real cross-sea isolated continuous beam bridge as the example, the analysis model of the sea-crossing bridge is established by ADINA software with the fixed-base assumption. Based on the Japanese KIK-net network, 7 submarine strong earthquake stations and 7 coastal land strong earthquakes with similar magnitude and epicenter distance are selected, each site conditions with 14 horizontal(independently considered EW and NS directions) seismic records. The seismic records are input along the longitudinal direction of the bridge for seismic response time history analysis. The seismic response of a sea-crossing isolated continuous beam bridge under different two ground motion input modes is studied, one is the offshore ground motions, the other is onshore ground motions. The maximum deformation and force of the bridge pier, the displacement response of the main girder and the maximum shear strain of the bearing are compared. It is known that, the responses of bridge structure subjected to the offshore ground motions are greater than that subjected to the onshore ground motions in most cases with response ratios being up to 1.3 to 1.9 times. Therefore the offshore seismic records should be input for seismic time history analysis of sea-crossing isolated bridge.更多还原