索承式桥梁腐蚀吊索安全性能评估

Assessment on safety performance of corroded cable for cable-supported bridge

腐蚀蚀坑是索承式桥梁吊索力学性能退化的主要原因。基于断裂力学和蚀坑等效,考虑腐蚀蚀坑影响,以吊索在荷载作用下的安全系数小于2.5作为吊索失效判据,建立腐蚀吊索承载力安全性能评估方法,并以袁州大桥钢丝腐蚀速率数据为基础,进行参数敏感性分析和算例计算,研究了各工况下吊索失效时的断丝数量和安全系数小于2.5的时间。结果表明,该方法相比较均匀腐蚀理论模型,考虑了钢丝腐蚀蚀坑对吊索承载力的影响,能够预测钢丝断裂数量和安全系数小于2.5的时间。

Corrosion pit is the main cause of mechanical performance degradation for the cable of cablesupported bridge.Considering corrosion pits andwith the safety factor of cable under load less than 2.5as failure criterion,the method for assessing the safety capability for cable was established based on equivalent crack for corrosion pit and fracture mechanics.The Yuanzhou bridge wire corrosion rate data was taker to perform the parameter sensitivity analysis.,The quantity of broken wires when cable failed and the time with safety coefficient less than 2.5were studied.The results showed that this method could predict wire fracture number and the time with safety coefficient less than 2.5and compared with uniform corrosion theory model,this mehtod provided theoretical reference for cable-supported bridge operation andmaintenance.