有轨电车小半径曲线梁桥减隔震措施对比研究

Comparative Study on Seismic Isolation Measures of Small Radius Curved Girder Tramway Bridge

为适应交通路网发展需求,小半径曲线桥被广泛应用,其中有轨电车小半径曲线桥占据较高的比重。为确保地震区有轨电车的抗震安全,常采用减隔震装置以减小地震响应。然而,不同装置类型和布置方式对减隔震效果存在较大差异,因此有必要深入研究优化策略。本文以某典型有轨电车小半径曲线桥为工程背景,基于多个单一减震装置有机组合,依据边墩控制位移、中墩降低内力的组合减震理念,提出了一种新型的组合减隔震装置,并选择适宜参数的摩擦摆支座(FPS)、铅芯橡胶支座(LRB)和液体黏滞阻尼器(FVD)三种减隔震装置,通过动力非线性时程分析,探究了各装置关键参数对于曲线桥减震效果的影响,并对采用不同减隔震装置的有轨电车小半径曲线桥地震响应进行对比分析。研究发现:本文提出的组合减隔震方案能够明显弥补单一减隔震装置的不足,达到更好的减隔震效果,值得在同类桥梁中推广应用;FPS与LRB对墩底内力控制效果较好,但会在一定程度上放大结构的墩梁相对位移;FVD对墩梁相对位移的控制效果更好,但对墩底内力的控制效果比其他两种减隔震装置差。

To suit the development needs of the transportation network,small radius curved bridges are widely used,with a large proportion being tramway bridges.To ensure the seismic safety of trams in earthquake prone areas,seismic isolation devices are often used to reduce seismic response.However,there are significant differences in the effectiveness of seismic reduction and isolation between different device forms and arrangements,so it is necessary to conduct in-depth research on optimization strategies.This article takes a typical small radius curved tramway bridge as the engineering background,and based on the organic combination of multiple single damping devices,a new type of combined damping and isolation device is proposed with concept of controlling displacement by side piers and reducing internal force by middle piers.Three types of damping and isolation devices with suitable parameters,namely friction pendulum bearings(FPS),lead rubber bearings(LRB),and liquid viscous dampers(FVD),are selected.Through dynamic nonlinear time history analysis,the impact of key parameters of each device on the seismic reduction effect of curved bridges is explored and the seismic responses of the curved bridges are analyzed.Research has found that the combined seismic reduction and isolation scheme proposed in this article can significantly compensate for the shortcomings of a single seismic reduction and isolation device,achieving better seismic reduction and isolation effects,and it is worth promoting and applying the proposed scheme in similar bridges;FPS and LRB have a good control effect on the internal force at the bottom of the pier,but they will amplify the relative displacement of the pier beam to a certain extent;FVD has a better control effect on the relative displacement of the pier beam,but its control effect on the internal force at the pier bottom is worse than the other two seismic isolation devices.