公路梁桥高阻尼橡胶支座优化配置研究

Optimal Configuration of High Damping Rubber Bearing for Highway Beam Bridge

减隔震设计是较为有效的抗震措施,高阻尼橡胶支座(HDR)亦因其较好的减隔震效果在公路梁桥中广泛应用。采用非线性时程分析法对软弱场地中配置不同减隔震支座的梁式桥进行地震响应分析,研究发现高阻尼橡胶支座的减隔震效果优于相同支承能力的板式橡胶支座。然而,无论是滑动式板式支座还是滑动式高阻尼橡胶支座均会导致相应桥墩处的支座位移过大,且各项地震响应与其他各墩差异较大,荷载在各墩间分配不均。通过改变边墩处高阻尼橡胶支座的刚度及类型,分析对比了支座的各项参数对桥梁结构地震响应的影响规律。研究发现全桥采用刚度相近的高阻尼橡胶支座时能够达到全桥各墩抗震性能的均衡、减小地震作用对桥梁结构及支座的破坏。

Seismic isolation design has been proved to be an effective earthquake resisting method,and high damping rubber bearings(HDR)have been widely use in bridges because its preferable seismic isolation effect.The dynamic time-history analysis has been taken by earthquake waves with different exceeding probability.The seismic response of highway beam bridges with different seismic isolation bearing have been analyzed,and the damping and isolation effect of high-damping rubber bearing was proved superior to laminated rubber bearing.However,the displacement of sliding bearings set on side piers were much more lager than the high-damping rubber bearings set on middle piers.As the seismic responses were different between side piers and middle piers,the load distribution of piers was nonuniform.The rigidity and type of high-damping rubber bearing on side piers were changed,and then the influence for seismic responses of bridge caused by bearings on side piers has been discussed.The study shows that load sharing percent is much more reasonable as high-damping rubber bearings were set on all the piers,and the damage of bridge and bearing were greatly decreaseswhen earthquake occurs.