重载铁路钢桁梁桥疲劳寿命预测方法及应用研究

Fatigue Life Prediction Method and Application of Steel Truss Bridge in Heavy Haul Railway

对朔黄铁路一座64 m单线下承式钢桁梁桥的疲劳寿命进行评估。基于运营列车的编组和运量,采用有限元软件计算得到评估杆件的应力历程,利用雨流计数法统计得到不同杆件的应力频谱,并采用合理的系数对应力幅进行修正,结合Miner线性累积损伤原理对钢桁桥的疲劳寿命进行评估。结果表明:下弦杆、斜杆和次横梁的理论剩余疲劳寿命在50年以上;吊杆高强度螺栓连接构造的理论剩余疲劳寿命为35年;纵梁跨中下翼缘高强度螺栓连接构造的理论剩余疲劳寿命已截止,其他构造理论剩余疲劳寿命均不足10年。对于开行重载运输的钢桁梁桥,纵梁及其连接部位是薄弱环节,应重点关注。

The fatigue life of a 64 m single track through steel truss bridge on Shuozhou-Huanghua railway was evaluated. Based on the marshalling and traffic volume of the operating train,the stress history of the assessed members was calculated by the finite element software,the stress spectrum of different members was obtained by the rain flow counting method,and the stress amplitude was corrected by a reasonable coefficient. The fatigue life of the steel truss bridge was evaluated by combining Miner’s linear cumulative damage principle. The results show that the theoretical residual fatigue life of the lower chord,inclined rod and secondary beam is more than 50 years. The theoretical residual fatigue life of the suspender high-strength bolt connection structure is 35 years. The theoretical fatigue life of the high-strength bolt connection structure of the lower flange of the longitudinal beam in the middle span has expired,and the theoretical residual fatigue life of other structures is less than 10 years. For the steel truss bridge with heavy haul transportation,the longitudinal beam and its connecting parts are the weak links of the whole steel truss girder,which should be paid attention to.