基于软钢挡块的中小跨连续梁桥横向抗震性能研究  

Research on Lateral Seismic Performance of Medium and Small Span Continuous Girder Bridges based on Mild Steel Bumpers

作　　者：苟建汶 鲁俊峰 许力文 GOU Jian-wen;LU Jun-feng;XULi-wen(Management Committee of Jingyang High-tech Industrial Park(Deyang Tianfu Jingcheng),Deyang 618000,China;Sichuan Jiaoda Engineering Detection Consulting Co.Ltd.,Chengdu 610031,China;Ya'an City Transportation Service Center,Ya'an 625000,China)

机构地区：[1]四川德阳旌阳高新技术产业园区(德阳天府旌城)管理委员会,德阳市618000 [2]四川交大工程检测咨询有限公司,成都市610031 [3]雅安市交通运输服务中心,雅安市625000

出　　处：《公路》2025年第2期121-126,共6页Highway

摘　　要：汶川中小跨桥梁震害表明,板式橡胶支座滑移可以起到隔震作用,但梁体位移普遍较大,钢筋混凝土挡块被撞坏后刚度急剧下降,易发生落梁风险。为此,提出一种基于软钢挡块和板式橡胶支座的新型抗震体系,以某强震区中小跨连续梁为例,建立三维空间有限元模型,通过非线性动力时程分析方法研究软钢挡块屈服强度、初始间隙及屈服后刚度比对桥梁横向地震响应的影响,并与钢筋混凝土挡块模型比较。结果表明,考虑挡块后,支座峰值位移和梁体残余位移均远小于无挡块模型,限位效果显著;随着挡块屈服强度和屈服后刚度比的增加,支座峰值位移和梁体残余位移明显减小,墩底弯矩响应则略有增加;随着挡块初始间隙的增加,支座峰值位移和梁体残余位移先减小后增大,墩底弯矩不断减小,甚至小于无挡块情况;相比于钢筋混凝土挡块,软钢挡块在屈服后强度不会退化,塑性耗能能力更强,在建议参数条件下展现出更优的横向抗震性能。It is found after the Wenchuan earthquake that the sliding of laminated rubber bearings can be the isolation device of medium and small-span bridges.However,the girder displacement is generally large,and the girder may fall-off due to the the stiffness drops sharply after the reinforced concrete(RC)stoppers damaged.Therefore,the isolation system based on mild steel stoppers and laminated rubber bearings is proposed.Taking a continuous bridge in a high-intensity seismic zone as an example,a threedimensional finite element model is established.The effects of yield strength,initial clearance,and postyield stiffness ratio on the lateral seismic response are studied through nonlinear time-history analysis and compared with a RC stopper model.The results indicate that the peak displacement of the bearings and the girder residual displacement are much smaller than those without stoppers,resulting in a significant restraint effect.As the yield strength and post-yield stiffness ratio increase,the peak bearing displacement and residual girder displacement decrease significantly,while the bottom bending moment increases slightly.With the increase in the initial clearance,the peak bearing displacement and girder residual displacement first decrease and then increase,while the bending moment decreases,even being smaller than the model without stoppers.Compared with RC stoppers,mild steel stoppers do not degrade in strength after yielding and exhibit stronger plastic energy dissipation,embodying superior lateral seismic performance with suggested parameters.

关 键 词：桥梁工程 连续梁桥 板式橡胶支座 软钢挡块 横向抗震性能 碰撞效应 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]