中小跨径梁桥基于准隔震理念的损伤状态耦合规律研究  

Damage state coupling characteristics of small-to-medium-span girder bridges based on the quasi-isolation concept

作　　者：徐略勤[1,2] 范磊 岳克锋 甘超 刘杰[1] XU Lueqin;FAN Lei;YUE Kefeng;GAN Chao;LIU Jie(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学山区桥梁及隧道工程国家重点实验室,重庆400074

出　　处：《地震工程与工程振动》2025年第2期74-85,共12页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51978113,52378482);重庆英才计划项目(cstc2022ycjh-bgzxm0133);重庆市研究生科研创新项目(CYS23473)。

摘　　要：为了在中小跨径梁桥的横向抗震体系中引入准隔震理念,首先结合典型震害统计特征,阐明了准隔震理念的基本内涵,明确了关键构件(即支座、挡块、桥墩)在桥梁抗震体系中的功能定位。然后以墩高、挡块强度为参数,构建了支座-挡块-桥墩体系的非线性分析模型。最后采用基于Copula函数的地震易损性分析方法,研究了支座、挡块和桥墩在地震作用下损伤状态的耦合规律,并根据系统层面的确定性易损性曲线,探讨了满足准隔震理念的挡块合理设计强度。研究表明:支座和挡块和桥墩在地震作用下存在显著的耦合作用关系,挡块强度对支座、桥墩的损伤状态有重要影响;当挡块强度由0增至30%的恒载反力时,支座损伤概率不断降低,其完全破坏概率的最大降幅为27.2%,而桥墩损伤概率则不断上升,其完全破坏概率的最大增幅达61.6%,挡块、支座和桥墩的损伤次序会逐渐转变为桥墩、挡块和支座;当挡块强度取值为15%~20%的主梁恒载反力时,支座的滑动隔震和桥墩的塑性耗能都被充分调动,此时支座-挡块-桥墩系统在地震中出现严重损伤的概率最低,相比无挡块工况降低了16.3%。To introduce the quasi-isolation concept in the transverse earthquake-resisting system of small-to-medium-span girder bridges,first the basic connotation of the quasi-isolation concept was elaborated based on the typical seismic damage statistical characteristics,and the performance roles of the critical elements(i.e.bearing,retainer and pier)were defined in the bridge earthquake-resisting system.Then,nonlinear analytical models were established for the bearing-retainer-pier systems considering the parameters of pier height and retainer capacity.Finally,the fragility analysis method based on the Copula functions was applied to investigating the coupling characteristics of the damage states of bearing,retainer and pier under earthquake actions,and the reasonable design capacity of retainer was explored according to the system-level deterministic fragility curves to satisfy the requirements of the quasi-isolation concept.The results showed that significant coupling relationships exist among the bearing,retainer and pier under seismic actions.The capacity of retainer has a notable impact on the damage states of bearing and pier.When the retainer capacity increases from 0 to 30%of the superstructural dead load reaction force,the damage probability of bearing decreases continuously,and a maximum decrease of 27.2%can be achieved at the complete damage state,while the damage probability of pier increases steadily with the maximum increase of 61.6%at the complete damage state.The damage sequence gradually changes from the retainer,bearing,pier to the pier,bearing and then the retainer.When the retainer capacity is designed as 15%~20%of the superstructural dead load reaction force,the bearing sliding isolation and the pier plastic energy dissipation can be fully mobilized,and the severe damage probability of the bearing-retainer-pier systems under the seismic actions is the lowest and reduced by 16.3%when compared to that of the case without retainers.

关 键 词：中小跨径梁桥 准隔震理念 损伤状态 挡块强度 地震易损性 COPULA函数 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]