基于概率断裂力学的老龄钢桥使用安全评估  

PROBABILISTIC FRACTURE MECHANICS ASSESSMENT OF SERVICE SAFETY FOR OLD STEEL BRIDGES

作　　者：王春生[1] 聂建国[1] 陈艾荣[2] 陈惟珍[2] 

机构地区：[1]清华大学土木工程系 [2]同济大学桥梁工程系,上海200092

出　　处：《工程力学》2006年第6期102-106,共5页Engineering Mechanics

基　　金：国家自然科学基金资助项目(50408028);清华大学-中大集团博士后科学基金资助项目(2004-3);长安大学科学基金资助项目(2004-18)

摘　　要：我国交通线上存在大量老龄钢桥,这些老龄钢桥承受着日益繁重的交通荷载,其疲劳剩余寿命已受到桥梁管理部门的高度重视。为确保老龄钢桥的使用安全,避免不必要的维护与更换,建立老龄钢桥疲劳剩余寿命与使用安全评估方法十分必要。建立了反映老龄铆接钢桥疲劳破坏机理的脆断和韧断概率失效模型,给出了用于疲劳可靠性分析的极限状态方程,合理确定了随机变量的参数取值。建立了铆接钢桥构件单角钢概率疲劳破坏模型,基于MonteCarlo算法实现了铆接钢桥构件单角钢疲劳断裂失效概率的计算,编制了相应的概率断裂分析程序SAPFF。进而将铆接构件概率断裂模型应用于上海市浙江路桥的时变疲劳可靠度分析,并给出了浙江路桥概率疲劳剩余寿命评估结果与维护对策。There are many old steel bridges on Chinese highway and railway lines. These old steel bridges are often required to carry an increasing volume of traffic, usually consisting of truck heavier than those considered in the original design. Therefore, the remaining fatigue life and service safety of old steel bridges is a topic of considerable importance, particularly for their operators. An improved method for the estimation of the actual fatigue life and safety of such structures are required in order to make their continued safe use possible while avoiding unnecessary repairs or replacements. According to the fatigue failure mechanism of riveted steel bridges, two probabilistic fatigue failure models -brittle and ductile are proposed. Moreover, the corresponding limit-state equation and the basic variables based on probabilistic fracture mechanics are identified, and the uncertainties associated with them are quantified. A single-angle probabilistic fatigue failure model （SAPFFM） of riveted bridge members is proposed＇. Furthermore, a reliability analysis program -SAPFF, based on Monte-Carlo method, is developed to compute the fatigue failure probability of SAPFFM. Then SAPFFM is used to predict the time fatigue reliability of main truss members of Zhejiang Road Bridge in Shanghai. Based on the assessment results, the probabilistic remaining fatigue life, inspection intervals and maintenance strategy are determined.

关 键 词：老龄钢桥 概率断裂力学 疲劳可靠度 概率疲劳剩余寿命 检测间隔 

分 类 号：U445.7[建筑科学—桥梁与隧道工程]