拱桥吊杆腐蚀疲劳可靠性评估方法研究

Corrosion Fatigue Reliability Assessment for Suspender in Arch Bridge

吊杆在外界腐蚀介质的侵蚀作用下疲劳抗力会明显下降。为提出考虑环境侵蚀作用下拱桥吊杆的疲劳可靠性评估方法,论文以四川省宜宾市某中承式拱桥为工程背景,基于车辆荷载和吊杆索力监测数据及更换的锈蚀吊杆的数据信息,建立了既有桥梁锈蚀后吊杆构件的疲劳抗力和荷载效应概率模型,并建立了考虑环境侵蚀作用下吊杆的疲劳可靠性功能函数。研究表明:短吊杆的疲劳可靠度指标小于长吊杆,考虑锈蚀作用时吊杆的疲劳寿命显著下降。

The fatigue resistance of suspender materials will be weakened under the environmental corrosion. In order to propose a method of fatigue reliability prediction for suspender under the environmental corrosion, a half-through arch bridge in Yibin city Sichuan province was analyzed. A function for predicting the suspender fatigue life was established based on the measured data of vehicle loads and strain data. The line relationship between vehicle number and strain data was established. A monotonic decreasing function was proposed to describe the variation of fatigue resistance under the influence of environmental corrosion. The research shows that the fatigue reliability index value of the short suspender is less than the long suspender. The calculation value of fatigue life for suspender declined considering the environment corrosion.