以一座多孔大跨度连续梁桥为工程背景,研究了抗震分析中是否考虑摩擦支座的摩擦效应对分析结果的影响,以及采用摩擦支座并联阻尼器和双曲面球型减隔震支座2种减隔震方案的减震效果。结果表明:对于多孔大跨度连续梁桥,考虑摩擦效应后固定墩的地震力显著小于不考虑时的分析结果;在考虑摩擦效应的基础上,2种减震方案均可减小固定墩的地震反应,而双曲面球型减隔震支座方案具有更优的减震效果;摩擦支座并联阻尼器方案减震效果不佳的主要原因是支座摩擦力和阻尼器阻尼力间存在90°的相位差。
A continuous girder bridge was selected as the practical engineering background.Influence of the frictional effect from frictional bearings on seismic analysis,seismic isolation effects of two methods that the bridge was respectively supported on frictional bearings with parallel dampers and double spherical aseismic bearings were studied.Results show that after taking frictional effect into account,seismic forces of the fixed pier are far smaller than those of response spectrum analysis.Considering frictional effect,the seismic isolation methods can reduce the seismic forces and double spherical aseismic bearing has better seismic isolation effect.The main cause why the seismic isolation effect from frictional bearings with parallel dampers is inoperative is that there is a phase difference of 90° between the bearing friction force and the damping force.