随机车流下公路钢桥疲劳可靠度分析  

Fatigue reliability assessment for highway steel bridges under stochastic traffic flow

作　　者：肖新辉[1,2] 鲁乃唯[1,3] 刘扬[1,2] 

机构地区：[1]长沙理工大学土木与建筑学院,湖南长沙410114 [2]长沙理工大学桥梁结构安全控制湖南省工程实验室,湖南长沙410114 [3]东南大学土木工程学院,江苏南京210096

出　　处：《浙江大学学报（工学版）》2016年第9期1777-1783,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家"973"重点基础研究发展规划资助项目(2015CB057704);国家自然科学基金资助项目(51378081);桥梁结构安全控制湖南省工程实验室(长沙理工大学)开放基金资助项目(14KD05)

摘　　要：为了建立车载下公路钢桥疲劳应力概率模型,将典型疲劳车辆改进为随机车流模型,提出基于响应面法(RSM)的随机车流下钢桥疲劳应力概率分析方法.建立考虑随机车流参数的疲劳损伤功能函数,分析交通量和车重增长对疲劳可靠度的影响.研究结果表明,基于RSM的有限元模型替代方法可以高效地分析随机车流下钢桥的疲劳应力;车重和交通量的增长对桥梁的疲劳可靠度有较大的影响,在交通量增长系数达到3%或车重增长系数达到0.4%时,某钢箱梁桥在设计基准期内的可靠指标低于目标可靠指标.随机车流模型在桥梁疲劳应力概率分析与可靠度评估中具有较好的适用性.A stochastic traffic flow model was presented and improved by the typical fatigue vehicles to es-tablish the probability models of fatigue stress for steel highway bridges under vehicle loads. The response surface method （RSM） was applied to analyze the probability of fatigue stress of steel highway bridges un-der the stochastic traffic flow. Fatigue damage performance functions were established by considering pa-rameters in the stochastic traffic flow model, which included the influence on fatigue reliability caused by the increase of traffic volume and vehicle weight. Results indicate that the RSM method is efficient for fa-tigue stress analysis of steel highway bridges under stochastic traffic flow. The increase of vehicle weight and vehicle volume has significant influence on the fatigue reliability of steel bridges. When the growth fac-tor of traffic volume is more than 3 % or that of traffic weight is more than 0. 4 % , the fatigue reliability in-dex of a steel bridge is less than the design reliability index. The stochastic traffic flow model is suitable for the probability analysis of fatigue stress and the fatigue reliability assessment of highway bridges.

关 键 词：梁桥工程 疲劳可靠度 随机车流 响应面法(RSM) 交通量 

分 类 号：U441[建筑科学—桥梁与隧道工程] U448.21[交通运输工程—道路与铁道工程]