基于评估基准期的既有梁桥时变可靠度评估方法

Time-dependent Reliability Evaluation Method of Existing Beam Birdge Based on Assessment Reference Period

针对基准时间参数不断变化的特点和各要素时间轴相统一的内在要求,开展基于评估基准期的时变可靠度评估研究.指出时变可靠度分析中抗力、荷载效应、目标可靠指标都是评估基准期的函数.基于等超越概率准则,建立了评估基准期的迭代求解方法;采用活载效应修正系数,建立了给定评估基准期内的车辆荷载效应模型;基于年失效概率相等准则,建立了给定评估基准期的目标可靠指标计算方法.引入材料退化模型,形成了在役RC梁桥剩余寿命分析技术.分析表明,所建议方法能够与现行可靠度标准体系相匹配,实用性较高.

According to the change of reference-time parameter and time axis consistency of factors,the time dependent reliability evaluation based on assessment-reference period is studied.It was pointed out that the resistance,load effect and target reliability index were all function of assessment reference period.Based on the equal exceeding probability principle,the assessment reference period iterative method was established.The vehicle load effect model during the given assessment reference period was proposed by the live load effect correction factor.Based on the equal year failure probability principle,the target reliability index calculation method was constructed for the given assessment reference period.By introducing the RC material degradation model,the remaining life analysis method for existing RC beam bridges was established.The analysis results show that the proposed method is availability,and matches with the reliability standards.