高烈度地震区高墩简支梁桥减隔震设计研究

Seismic Isolation Design Study of High Pier Simply Supported Beam Bridge in High Seismic Intensity Area

为研究高烈度区高墩铁路简支梁桥在地震作用下的结构响应状况,选取某车站特大桥为研究背景,根据桥梁多遇、罕遇地震作用下的结构响应幅值,开展桥梁延性设计方案和减隔震方案两种情况下的内力和配筋对比。结果表明:高烈度地震区高墩桥梁,采用延性设计时,配筋率需求过高,设计难度大,且下部结构工程量增加较多,经济性较差。采用回型钢耗能双曲面减隔震支座进行减隔震设计时,桥墩与桩基内力较普通支座有显著的减小,墩梁相对位移随墩高的增加呈递增趋势,纵向最大位移0.293m,横向最大位移0.224m,未超过0.3m的设防目标。采用减隔震设计,可以有效降低结构地震响应,减小设计难度,提高结构安全性,提升经济性能。

In order to study the structural response of high pier railway simply supported beam bridge in high seismic intensity area,a bridge is selected as the research background.According to the structural response amplitude of the bridge under frequent and rare earthquakes,the internal force and reinforcement of the bridge under the two conditions of ductility design and seismic isolation design are compared.The results show that when the ductility design is adopted for high-pier bridges in high seismic intensity areas,the demand for reinforcement ratio is too high to achieve,the design is difficult,the engineering quantity of the substructure increases significantly,and the economy is poor.When the seismic isolation design is carried out by using the return steel energy dissipation hyperboloid seismic isolation bearing,the internal force of the pier and the pile foundation is significantly reduced compared with the ordinary bearing.The relative displacement of the pier and beam increases with the increase of the pier height.The maximum longitudinal displacement is 0.293 m,the maximum lateral displacement is 0.224 m,and the fortification target of 0.3 m is not exceeded.The seismic isolation design can effectively reduce the seismic response of the structure,reduce the design difficulty,improve the structural safety and economic performance.