基于无损探测信息的既有钢桥构件疲劳可靠度更新评估  

Fatigue reliability updating evaluation using nondestructive inspections for existing steel bridges

作　　者：王春生[1] 刘鑫[1] 俞欣[1] 徐岳[1] 

机构地区：[1]长安大学桥梁与隧道陕西省重点实验室,陕西西安710064

出　　处：《土木工程学报》2010年第8期81-87,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(50408028);高等学校全国优秀博士学位论文作者资助项目(2007B49)

摘　　要：现代无损探测技术不仅可以检测结构中存在的疲劳裂纹,而且无损探测信息可用于疲劳可靠度的更新评估。研究表明基于贝叶斯定理的概率断裂力学评估方法能有效地引入无损检测结果,实现裂纹扩展模型和相应参数的更新。本文基于疲劳裂纹无损检测的概率特性和贝叶斯定理,建立基于贝叶斯定理的既有钢桥构件疲劳可靠度更新模型,从而完善既有钢桥疲劳寿命与使用安全评估方法体系。以上海市浙江路桥为例,按本文给出的疲劳可靠度更新模型,计算得到第三吊杆(M3L3)检测更新后的β-T曲线。由-βT曲线可知,当未检测到裂纹时,相应的疲劳可靠度增大;当检测到未知裂纹时,相应的疲劳可靠度减小;当检测到具体裂纹时,疲劳可靠度也有明显变化。Through modern nondestructive inspection（NDI） techniques,the fatigue flaws can be detected for existing structures,and fatigue reliability assessment can be updated.The probabilistic fracture mechanics method based on the Bayes theorem with the information from nondestructive inspections can be employed to update the crack growth models and relevant parameters effectively.In this paper,based on the probabilistic characteristics for NDI techniques and the Bayes theorem,a fatigue reliability updating assessment model for existing steel bridge components is proposed for existing steel bridges.In the case study,the β-Tcurves of the third suspender（M3L3） of the Zhejiang Road Bridge is determined.The results showed that the fatigue reliability will increase with no flaws detected,decrease with unknown flaws detected,and change remarkably with flaws detected.

关 键 词：既有钢桥 无损探测 贝叶斯定理 疲劳可靠度 更新 

分 类 号：U447[建筑科学—桥梁与隧道工程] U448.36[交通运输工程—道路与铁道工程]