基于行车安全性的高铁桥梁横桥向减隔震体系研究

Transverse seismic isolation system of high-speed railway bridge based on train running safety

针对目前最常用的32 m跨径高铁简支梁桥,同时考虑对行车安全不利的路桥过渡段和墩高改变处,对高铁桥梁的行车安全性能进行了评价;分析了铅芯橡胶支座、摩擦摆支座等常规减隔震方案在高铁桥梁中运用的可行性。分析结果表明,采用盆式橡胶支座的高铁桥梁在地震作用下轨道变形和轨道横向加速度较大,无法满足高速运行的列车的行车安全性要求;采取常规减隔震措施之后,尽管地震响应有所降低,但在路桥过渡段依然无法满足列车的行车安全性要求。鉴于此,研发了抗冲击多向耗能阻尼器,与盆式支座相结合,提出了可以满足列车行车安全性的高铁桥梁横桥向减隔震体系。该体系可在地震作用时盆式支座剪断瞬间承受较大的冲击力,保证体系转换过程中桥梁结构的刚度不发生突变,控制轨道变形不超过允许的限值,保证列车的行车安全性。

Here,aiming at the most widely used 32 m-span high-speed railway simply supported girder bridge,considering transition segments of road and bridge and change places of pier height harmful to train running safety,the safety performance of high-speed railway bridge was evaluated and the feasibility of applying conventional seismic isolation schemes,such as,lead core rubber bearings and friction pendulum bearings in high-speed railway bridge was analyzed.The results showed that track deformation and track lateral acceleration of high-speed railway bridge with pot type rubber bearings are larger,they can’t meet running safety requirements of high-speed trains;after taking conventional seismic isolation measures,the bridge seismic response is reduced,but running safety requirements of train can’t be satisfied at transition segments of road and bridge.Therefore,the anti-impact multi-directional energy-dissipating damper was developed,using it combined with pot type bearing,a transverse seismic isolation system for high-speed railway bridge was proposed to meet requirements of train running safety.It was shown that under action of earthquake,the proposed system can bear a larger impact force at the moment of pot type bearing being cut off,ensure the stiffness of the bridge structure not having mutation in conversion process of the system,control track deformation not exceeding the allowable limit value,and ensure the running safety of trains.