基于修复函数的连续梁桥抗震韧性因素及改进评估研究

Research on seismic resilience factors and improved evaluation of continuous beam bridges based on recovery function

为了研究三种修复函数的功能,以一座三跨钢筋混凝土连续梁桥为工程背景进行分析。通过增量动力分析法(Incremental Dynamic Analysis,IDA)进行时程分析,结合构件损伤判定准则及一阶界限法计算桥梁系统易损性。基于易损性考虑桥梁震后功能损失及震后修复,将目标功能、耽搁时间作为影响因素,研究三种修复函数的性质。结果表明:不同修复函数对目标功能的敏感程度不同,指数型最大,其敏感系数分布于60%~80%间、直线型居中,敏感系数稳定在60%、三角型最小,敏感系数小于10%;耽搁时间对修复函数的影响程度为指数型>直线型>三角型,且各修复函数抗震韧性的耽搁时间节点存在依次为90d、70d、40d;改进的抗震韧性评估结果属于合理范围,其考虑了桥梁破坏状态所受地震动强度变化的影响,克服了三种修复函数使用范围的局限性,为震后连续梁桥的修复提供一定的理论依据。

In order to research the function of three recovery functions,a three-span reinforced concrete continuous beam bridge is taken as an engineering background for analysis.The time-history analysis is carried out by using incremental dynamic analysis(IDA),and the vulnerability of bridge system is calculated by combining the component damage criterion and the first-order boundary method.Considering the post-earthquake functional loss and post-earthquake recovery of bridges based on vulnerability,the target function and delay time are taken as influencing factors to study the properties of three recovery functions.The results show that the sensitivity of different recovery functions to the target function is different.The exponential type is the largest and its sensitivity coefficient is distributed between 60%and 80%.The linear type is in the middle and its sensitivity coefficient is stable at 60%.The triangular type is the smallest and its sensitivity coefficient is less than 10%.The influence degree of delay time on the recovery function is exponential>linear>triangular,and the delay time nodes of seismic resilience of each recovery function are 90 days,70 days and 40 days.The improved seismic resilience evaluation results are reasonable.It considers the influence of seismic intensity change on the failure state of bridges,and overcomes the limitations of three recovery functions.The results provide a theoretical basis for the recovery of continuous girder bridges after earthquakes.