大跨度铁路钢桥疲劳计算方法及关键参数

疲劳问题是钢桥设计中需要重点关注的问题。对日本、欧洲和我国铁路钢桥疲劳计算方法及相关参数进行了调研分析,明确了各国铁路钢桥在疲劳计算方法和相关参数选择方面的异同。以我国一座千米级跨度铁路钢桁梁悬索桥为例,对其加劲梁杆件的疲劳受力特征、恒活载比及应力比进行了计算分析。研究结果表明:部分杆件在单线和双线荷载作用下疲劳受力特征不一致,恒活载比和应力比超出了我国现行规范的范围。针对这种情况,提出了我国大跨度铁路钢桥的疲劳计算方法调整建议,在此基础上对大跨度钢桥疲劳计算中涉及到的相关参数进行了梳理分析,提出了需要开展研究的参数包括损伤修正系数、多线系数、板厚系数等。提出的大跨度铁路钢桥疲劳计算方法及相关参数研究建议,可为下一步疲劳设计参数的研究及后续规范的修订补充提供参考。

Fatigue Calculation Method and Key Parameters of Long-span Railway Steel Bridge

Fatigue problem is a key problem in the design of steel bridges.Fatigue calculation methods and relevant parameters of railway steel bridges in Japan,Europe and China were investigated and analyzed.The similarities and differences of fatigue design calculation methods and relevant parameter selection of railway steel bridges in various countries were grasped.The fatigue characteristics,dead-live load ratio and stress ratio parameters of the stiffening beam members of a long-span suspension bridge in China were calculated and analyzed.The results show that the fatigue characteristics of some members under single line and double line loads are inconsistent,and the dead-live load ratio and stress ratio parameters are beyond the scope of the current code.According to the results,the adjustment suggestions on the fatigue calculation method of long-span railway steel bridges in China were put forward.On this basis,the relevant parameters involved in the fatigue calculation of long-span steel bridges were analyzed,and the parameters that need to be studied include damage correction coefficient,multi-line coefficient,plate thickness coefficient,etc.The fatigue calculation method and related parameters of long-span railway steel bridge that need to be studied were proposed,which can provide a reference for the design of bridges and revision and supplement of codes.