长联公铁两用钢桁梁桥采用速度锁定器装置减震性能研究

长联公铁两用钢桁梁桥固定墩地震响应大,抗震设计困难。通过设置速度锁定装置,并对各种速度锁定器布置方案进行比选分析,研究该类桥梁桥墩采用速度锁定器装置后的减震性能。由于设置速度锁定器装置的活动墩的分担,各方案整体减震率可达到20.5%～47.1%。如锁定墩(设置速度锁定器装置的活动墩)墩高相比固定墩和其他锁定墩墩高矮很多,或者锁定墩一侧未采用速度锁定器装置的活动墩较多,则该锁定墩的地震响应可能超过原固定墩。该类桥梁确定锁定器布置方案时应综合考虑内力和位移的减震效果、锁定力大小,并同时兼顾公路层和铁路层梁-墩相对位移的大小等因素的影响。对长联公铁两用钢桁梁桥,采用速度锁定器装置并优化其布置方案后,可取得较好的减震效果。

Research on Seismic Mitigation Performance of Long-connected Road-rail Steel Truss Bridges with Lock-up Devices

For long-connected road-rail steel truss bridges, it's difficult to conduct seismic design due to large seismic response of the fixed pier. Through the adoption of lock-up devices and the optimization of layout schemes, the seismic mitigation performance of this type of bridge pier equipped with lock-up devices is studied. Owing to the sharing of movable piers, the overall mitigation rates of different schemes can reach 20.5%～47.1%. If the height of lock-up piers is much lower than the fixed pier and other lock-up piers, or the number of neighboring movable piers without lock-up devices is large, the seismic response of lock-up piers will probably be greater than that of the fixed pier. For the determination of lock-up devices layout schemes, seismic mitigation rates of internal forces and displacements, lock-up force tonnage, and beam-pier relative displacements of the railway and highway floors should all be considered. Good mitigation performance can be achieved by using lock-up devices and optimizing layout schemes.