铁路简支梁桥中减震榫的设计及其减震性能研究

Design and Seismic Mitigation Performance Study of Shock Absorber for Railway Simply-Supported Beam Bridge

针对高速铁路桥梁整体刚度大导致地震反应相应较大的问题,提出一种适用于高速铁路桥梁的软钢阻尼器——减震榫,并与滑动支座共同作用,组成一种新的减震支座系统。采用双线性滞回恢复力模型描述减震榫的滞回耗能特性,以某四跨高速铁路简支梁桥为例,分析减震榫-滑动支座系统的减震性能及墩高对减震效果的影响。分析结果表明:采用减震榫-滑动支座体系,墩底剪力、墩底弯矩及墩顶位移均大幅减小,减震效果十分明显;合理地设置减震榫的参数,可实现支座系统的多级抗震性能指标;墩高对减震榫的减震效果影响较大,针对不同的桥梁结构,减震榫设置应单独进行参数分析以达到最优的减震效果。

In the light of the problem that the seismic response of high-speed railway bridge is accordingly great since the global rigidity of the bridge is great, a kind of the mild steel damper, the shock absorber, which is suitable for the bridge is proposed. The shock absorber is designed to work together with the slide bearing and a new seismic mitigation system of the shock absorb- er-slide bearing is therefore formed. The bilinear hysteretic resilience model is used to represent the hysteretic energy dissipation characteristic of the shock absorber and by way of example of a four-span high-speed railway simply-supported beam bridge, the seismic mitigation performance of the shock absorber-sliding bearing system and the influences of the pier height on the seismic mitigation effect of the system are analyzed. The results of the analysis demonstrate that after the new seismic mitigation system of the shock absorber-slide bearing is applied, the shear force and the moment in the pier footing and the displacement of the pier top greatly decrease and the seis- mic mitigation effect is quite significant. The proper design of the parameters of the shock ab- sorber can achieve the multi-level seismic resistance indices of the seismic mitigation system. The pier height has great influences on the seismic mitigation effect of the shock absorber and in such case, for the arrangement of the shock absorber, the related parametric analysis should be carried out respectively in accordance with the different bridge structures in order to achieve the optimal effect of the seismic mitigation.