大跨悬索桥索梁锚固区疲劳养护概率优化方法  

Fatigue Maintenance Probabilistic Optimization of Cable-girder Welded Anchorage Zones in Suspension Bridges

作　　者：曾勇[1,2] 顾安邦[1] 陈艾荣[3] 谭红梅[1] 

机构地区：[1]重庆交通大学山区桥梁与隧道工程省部共建国家重点实验室培育基地,重庆400074 [2]重庆交通大学山区桥梁结构与材料教育部工程研究中心,重庆400074 [3]同济大学桥梁工程系,上海200092

出　　处：《土木建筑与环境工程》2014年第2期21-27,共7页Journal of Civil,Architectural & Environment Engineering

基　　金：国家973计划前期研究专项课题(2012CB723305);交通运输部应用基础研究项目(2013319814180);国家留学基金资助项目(201308505149);浙江省公路管理局科研项目(2011H41)

摘　　要：合理的桥梁养护规划应在养护费用与失效风险之间找到一个合理的平衡。将养护费用分为检测费用,维修费用与失效费用,将线弹性断裂力学、结构可靠度理论、全寿命成本分析法结合起来,提出了基于全寿命周期成本的焊接构件疲劳养护概率优化的方法。考虑了检测概率、养护决策者的维修意愿、维修措施概率和失效概率等多种因素,把桥梁养护优化问题变为在焊接结构或构件满足在生命周期内最小允许可靠度的基础下,养护总费用最小的问题,并提出了简化计算方法。以青草背长江大桥索梁锚固区的关键疲劳细节养护为例,研究了主要参数对最优检测时刻的影响,研究结果表明,考虑了失效成本后,最优疲劳养护时刻提前,折现率对养护费用影响明显。当车辆荷载逐年增加时,索梁锚固区在设计基准期内疲劳破坏风险增大,应引起足够的重视。it is necessary to balance the failure risk and the maintenance expensive. A methodology for reliability based maimenanee optimization of steel bridge welded joints subjected to fatigue is proposed considering linear elastic fracture mechanics （LEFM）, the structure reliability, life cycle cost method and maintenance strategies. The maintenance cost is divided into inspection, repair and failure sections according to the whole life cycle cost methodology. And the maintenance strategy is transformed to the minimum expected lifetime costs with a constraint of the minimum acceptable reliability index. An case concerning to a transverse stiffener of bottom flange welded joint of Qingeaobei bridge is studied with a certain number of simplifications. Some sensitivity analysis is provided. Among all the parameters, discount rate is the most remarkable.

关 键 词：线弹性断裂力学 可靠度 索梁锚固区 维修策略 疲劳 折现率 概率优化 

分 类 号：U448[建筑科学—桥梁与隧道工程]