高速铁路(100+200+100)m连续梁-拱桥抗震性能分析

徐宿淮盐铁路徐洪河特大桥(100+200+100)m连续梁-拱位于郯庐断裂带影响范围内,桥位处地震动峰值加速度为0.34g,综合考虑结构重要性并满足“大震不倒”的抗震设防目标,制定了大跨度梁拱组合结构三水准的抗震设防标准。利用空间有限元程序对桥梁进行动力特性分析及减隔震措施方案比选,并运用反应谱法和时程分析法对多遇地震作用下结构内力响应进行对比分析。结果表明,采用双曲面球形减隔震支座与设置缓冲弹塑性挡块结合的抗震措施,可有效减小地震力作用下的结构内力响应,并使地震力作用下梁体位移满足抗震设防标准要求。本桥采用的抗震设防标准及减隔震设计方法,为高烈度区重要桥梁的抗震设计提供了参考。

Analysis on Seismic Performance of(100+200+100)m Continuous Beam-arch Bridge on High-speed Railway

The(100+200+100)m continuous girder-arch of Xuhonghe Bridge on the Xuzhou-Suqian-Huaian-Yancheng Railway is located within the area affected by the Tan-Lu fault zone.The peak ground acceleration motion at the bridge location is 0.34g.Considering the importance of the structure and satisfying the requirement of "anti-collapse to tall buildings under severe earthquake",the seismic fortification target of the three-level seismic fortification standard for long-span continuous girder arch bridge was formulated.The finite element analysis program was used to analyze the dynamic characteristics of the bridge,compare and select the seismic isolation and isolation measures,and use the response spectrum method and time domain analysis method to compare and analyze the internal force response of the structure under the action of multiple earthquakes.The results shows that the combination of the hyperbolic spherical isolation support and the cushioning elastic-plastic stop can reduce the internal force response of the structure and make the beam displacement meet the requirements of seismic fortification standard under the seismic force.The seismic fortification standards and seismic isolation design methods adopted by the bridge provide a reference for the seismic design of important bridges in the high earthquake-intensity area.