悬索桥主缆索寿命期内可靠度指标确定方法  

Determination Method of Reliability Index of Main Cable Life of Suspension Bridge

作　　者：易富 孙悦 杜常博 李军[2] YI Fu;SUN Yue;DU Changbo;LI Jun(School of Architecture and Transportation,Liaoning Technical University,Fuxin 123000,China;School of Civil Engineering,Liaoning Technical University,Fuxin 123000,China)

机构地区：[1]辽宁工程技术大学建筑与交通学院,辽宁阜新123000 [2]辽宁工程技术大学土木工程学院,辽宁阜新123000

出　　处：《防灾减灾工程学报》2020年第3期358-364,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51774163)资助。

摘　　要：以某工程为背景,应用Midas civil并基于主缆面积、弹性模量和极限强度的时变模型对主缆进行腐蚀模拟,其后,在车辆疲劳荷载作用下得到疲劳应力幅,并对Manson-Coffin公式进行修正得到主缆在寿命期内的S-N曲线,由此估算出主缆关键位置在寿命期内的疲劳寿命,利用Matlab编制主缆关键位置在寿命期内的失效概率和可靠度指标计算程序。研究表明:除锚固和索塔位置外,主缆其它位置应力均呈对称分布;在寿命期为100年时,索塔位置疲劳应力幅变化量最大,锚固位置疲劳寿命最低且可靠度指标退化最快;主缆可靠度指标与使用年限、当地环境、主缆长度以及基准长度存在一定关系,最终给出了悬索桥主缆索在腐蚀条件下的可靠度指标计算公式。In order to determine the calculation method of reliability index of the main cable of a suspension bridge under corrosion condition,the corrosion simulation of main cable is carried out by using Midas civil and time-varying model of main cable cross-sectional area,modulus of elasticity and ultimate strength based on the background of a certain project. The fatigue stress amplitude is obtained under the fatigue load of vehicle,and the S-N curve of the main cable during the life cycle is obtained by modifying Manson-Coffin formula,and the fatigue life of the key position of the main cable during the life cycle is estimated. The calculation program of failure probability and reliability index of key position of main cable during life cycle is compiled by MatLab. The research results shows that except for anchoring and cable tower position,the stresses in other positions of the main cable are symmetrically distributed,and when the life period is 100 years,the variation of fatigue stress amplitude in the cable tower position is the largest,the fatigue life of the anchor position is the lowest and the reliability index is the fastest. The reliability index of main cable is related to service life,local environment,main cable length and reference length. The calculation formula of reliability index of the main cable of suspension bridge under corrosion condition is put forward. The research results provide certain reference for practical engineering.

关 键 词：悬索桥 主缆腐蚀 S-N曲线 疲劳寿命 可靠度指标 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]