中小跨径双柱式高墩桥梁横系梁对抗震性能的影响

Influence of Collar Beam of Double Column High-rise Pier Bridge with Short Span on Seismic Performance

通过对地震中双柱墩桥梁的震害调查分析总结认为在双柱式高墩之间加设横系梁对桥梁下部结构在地震作用下的受力状态具有很大影响。采用SAP2000有限元软件对某跨径为30 m双柱式高墩连续梁桥进行模态分析和反应谱分析,分别讨论了横系梁的数量、不同的布置方式以及不同的截面几何尺寸对桥墩在设计地震动作用下的各主要关键截面处内力的影响。计算结果表明：在双柱式高墩之间加设横系梁对桥梁下部结构的内力分配影响很大,尤其是在地震作用下,合理设计横系梁能够有效的提高横桥向刚度,调整下部结构内力,并且先于墩身进入塑性工作状态消耗地震动能量输入来提高桥梁的抗震性能。对不同模型计算结果进行比较分析可知在0.3H和0.8H处布置一道相对于墩身刚度为0.3~0.6的横系梁,对桥梁结构的地震响应最为有利,可为双柱式高墩桥梁的设计提供一定的参考。

By analyzing and summarizing the seismic damage of double column bridge with high-rise piers,it is believed that collar beams designed between double column high-rise piers have great influence on the strained condition of substructure suffered from earthquake action.SAP2000,one of finite element softwares,was used to perform modal analysis and response spectrum analysis for a 30 m long double columns high-rise pier continuous beam bridge.The number,location and section dimension of collar beam which have influence on internal force at critical cross-sections of piers in design earthquake action were discussed.The analysis result reveals that collar beams contribute a lot to the distribution of internal force of the substructure,especially when suffered earthquake action,well-designed collar beams can effectively improve the transverse stiffness,adjust the internal force of the substructure,and dissipate earthquake energy when the collar beams work in a plastic state before the column piers to improve the seismic performance of the whole bridge.By comparing the results of different finite element models,it is concluded that when one collar beam whose stiffness is about 0.3~0.6 to the column pier is fixed at 0.3H and 0.8H,it is very beneficial to the seismic performance of bridge.This work may be valuable for the design of double column high-rise pier bridge.