公轨两用拱桥吊杆的疲劳分析

提出了一种公轨两用拱桥吊杆的疲劳分析方法。依据交通流量调查和相关规范中汽车及轻轨车荷载谱的规定,基于Monte-carlo原理,模拟产生了通过桥梁的双向多车道汽车车流及双向轻轨车车流。针对典型吊杆的影响线开展模拟车流加载,得到杆件应力历程,通过泄水法得到杆件应力谱,按照Palmgren-Miner线性累积损伤理论,计算得到各吊杆的等效应力幅并进行设计基准期内的损伤度评估。以某公轨两用拱桥进行实例分析,同时考虑6线行车道公路荷载和双线轻轨荷载,对吊杆开展了疲劳分析。计算结果表明:采用模拟车流法可方便开展公轨两用特大桥构件的疲劳分析和疲劳剩余寿命评估。

Fatigue analysis of suspender of arch bridge used for highway traffic and light-railway traffic

Fatigue analysis method of suspenders of arch bridge used for highway traffic and light-railway traffic was presented.According to the traffic flow surveys and relevant norms on the load spectrum,the bi-dimensional multi-line road vehicle traffic flows and light-rail traffic flows were generated based on Monte-carlo method.The stress time history of suspenders was obtained through the loads of traffic flow were added on the influence line of the suspenders,and the stress spectrum was computed through the reservoir method.Finally,the equivalent stress amplitude was calculated in accordance with the Palmgren-Miner linear cumulative damage theory,and the assessment of the damage was performed during the design reference period.An arch bridge used for highway traffic and light-railway traffic was selected as case study.Fatigue analysis of suspenders was completed taking into account both the six-lane highways load and two light-rail load.The results show that the approach of simulated traffic flow can be used conveniently to perform fatigue analysis and fatigue residual life assessment of large span bridge used for highway traffic and light-railway traffic.