考虑PSI的深水高墩大跨桥梁地震易损性分析  

Seismic fragility analysis for high-pier and long-span bridges in deep water considering pile-soil interaction

作　　者：吴文朋 梁鹏[2,3] 龙士国 张旭辉 WU Wenpeng;LIANG Peng;LONG Shiguo;ZHANG Xuhui(National-local Joint Engineering Research Lab for Long-term Performance Improvement Technology for Bridges in Southern China,Changsha 410014,China;College of Civil Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China;Hunan Communications Research Institute Co.,Ltd.,Changsha 410007,China)

机构地区：[1]长沙理工大学南方地区桥梁长期性能提升技术国家地方联合工程实验室,长沙410014 [2]湘潭大学土木工程与力学学院,湖南湘潭411105 [3]湖南省交通科学研究院有限公司,长沙410007

出　　处：《振动与冲击》2020年第19期210-217,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(51708477);中国博士后科学基金面上项目(2018M640756);湖南省科技重大专项(2017SK1010);湖南省教育厅科研项目(18C0099);沙理工大学南方地区桥梁长期性能提升技术国家地方联合工程实验室开放基金项目(16KF02)。

摘　　要：以某深水高墩大跨连续刚构桥梁为工程背景,考虑桩-土相互作用(PSI)、动水压力以及二者联合作用效应的影响,基于OpenSEES源代码分析平台建立有限元模型,随机选取100条近场地震波来考虑地震动输入的不确定性,以峰值地面速度(PGV)作为地震动强度参数,然后分别以墩顶、墩底曲率以及支座相对位移作为损伤指标,建立了桥梁不同构件的概率地震需求模型和地震易损性曲线,对深水桥梁的抗震性能进行了分析和评估。研究结果表明:深水桥梁的动水压力效应会增大桥墩的地震失效概率,但支座的失效概率会略有降低;考虑桩-土相互作用时墩底截面和支座的失效概率会有所减小,但墩顶的失效概率会有所增加;动水压力和桩-土相互作用均对支座易损性的影响相对较小;动水压力对高墩桥梁易损性的影响比桩-土相互作用要大。A certain high-pier long-span continuous rigid frame bridge in deep water was taken as engineering background,considering effects of pile-soilinteraction(PSI),dynamic water pressure and their joint action effect,the finite element analysis model for the bridge was built based on OpenSEES source code analysis platform.100 near-field earthquake wave records were randomly selected to consider the uncertainty of seismic input,and the peak ground velocity(PGV)was chosen as the seismic intensity parameter.Then,curvatures of both top and bottom of high-pier,and relative displacements of supports were taken as damage indexes to establish probabilistic seismic demand models and seismic fragility curves for the bridge’s different components,and analyze and estimate the seismic performance of the bridge in deep water.The study results showed that dynamic water pressure effect of the bridge in deep water can increase seismic failure probabilities of bridge piers,but failure probabilities of supports can drop slightly;when considering PSI,failure probabilities of pier bottoms and supports can be reduced,but failure probabilities of pier topscan grow;dynamic water pressure and PSI have relatively smaller effects on support vulnerability;effects of dynamic water pressure on the vulnerability of high-pier bridgesare greater than those of PSI.

关 键 词：高墩大跨桥梁 近场地震 地震易损性 动水压力 桩-土相互作用 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]