高墩刚构桥考虑材料劣化的时变抗震性能分析  

Time-dependent seismic performance analysis of rigid frame bridge with high piers considering the effect of material deterioration

作　　者：徐略勤[1] 李建中[2] XU Lueqin;LI Jianzhong(School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, China;State Key Laboratory for Disaster Reduction in Civil Engineering (Tongji University), Shanghai 200092, China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]土木工程防灾国家重点实验室(同济大学),上海200092

出　　处：《地震工程与工程振动》2019年第2期194-202,共9页Earthquake Engineering and Engineering Dynamics

基　　金：国家重点研发计划重点专项子课题(2016YFC0802206-3);重庆市基础与前沿研究计划项目(cstc2015jcyjA30014)~~

摘　　要：为了研究材料性能劣化对桥梁抗震性能的影响,以某高墩刚构桥及其服役环境为背景,分别计算得到了钢筋和混凝土的材料劣化时变规律,采用OpenSEES建立了不同服役年限的桥梁分析模型,基于推倒分析和增量动力分析研究了材料性能劣化对桥梁时变抗震性能的影响规律。研究表明:随着服役年限的增长,体系推倒曲线的等效屈服强度和屈服变形因劣化而不断下降,最大降幅均超过15%,而构件的等效屈服弯矩和等效屈服曲率最大分别下降了12.47%和19.88%;材料劣化在体系和构件两个层面上降低了桥梁的屈服性能,而对桥梁的初始刚度和动力特性的影响很小;当桥梁处于弹性状态时,材料劣化的影响可以忽略,当桥梁进入塑性状态后,材料劣化的影响随着桥梁塑性发展程度的加深而不断增大,墩底曲率延性系数最大增幅超过40%。因此,材料劣化对高烈度地区和采用延性设计方法的桥梁抗震而言是不可忽视的影响因素。To investigate the influence of material deterioration on the seismic performance of bridges, the time-dependent deterioration models were proposed respectively for the steel and concrete materials according to a rigid frame bridge with high piers serving in a particular environment. The OpenSEES software was used to establish analytical models for the bridge corresponding to different service years. The pushover analysis and incremental dynamic analysis methods were applied to reveal the effect of material deterioration on the seismic response of the bridge. The studies show that with a longer service life the equivalent yield strengths and yield deformations of pushover curves are decreased by more than 15%. The equivalent yield moments of the bridge elements decline due to material deterioration by a maximum of 12.74% while the equivalent yield curvatures decline by a maximum of 19.88%. The effect of material deterioration is mainly found on decreasing the yield properties of the bridge in both levels of structure system and structural elements. And the initial stiffnesses and the dynamic characteristics of the bridge are barely impacted by the material deterioration. When the bridge is in its elastic range, the effect of material deterioration can be ignored. But when the bridge deforms into its plastic range, the effect of material deterioration will be amplified by a larger degree of plasticity development, for example the curvature ductility factors of the pier columns are increased by more than 40%. Therefore, the effect of material deterioration cannot be ignored for the seismic performance evaluation of bridges located in high-seismicity zones or designed based on the ductility philosophy.

关 键 词：高墩刚构桥 材料劣化 抗震性能 推倒分析 增量动力分析 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]