行车荷载下大跨钢桁架吊杆拱桥动力响应分析

Dynamic Response Analysis of a Long-span Steel Truss Suspension Arch Bridge Under Traffic Loads

为研究行车荷载下大跨钢桁架吊杆拱桥桥面动力响应,以武汉江汉七桥为工程实例,建立三维精细化有限元模型,将车辆通过钢桁架桥的过程简化为车辆荷载对行驶区域对应的集中力和线荷载,研究大跨钢桁架吊杆拱桥动力响应。结果表明:不同加载方式下,行车荷载产生的桥面弯矩峰值曲线相近,且最大值均出现在桥墩附近;边跨加载范围内,集中力加载方式在低速时对非加载侧的影响较小,而线荷载加载方式对整个桥面都有影响;跨中加载范围内,不同加载方式的位移响应最值包络曲线相似,但是集中力加载下峰值要明显大于线荷载加载下的值。结果可为该工程及类似桥梁工程在其寿命期内的检测及维护提供一定的参考。

To investigate the dynamic response of a long-span steel truss suspension arch bridge under traffic loads,the Wuhan Jianghan No.7 Bridge was taken as an engineering example,and a three-dimensional refined finite element model was established to simplify the process of vehicles passing through the steel truss bridge as concentrated force and line load corresponding to the driving area.The dynamic response of the long-span steel truss suspension arch bridge was studied.The results show that under different loading modes,the peak bending moment curves generated by traffic loads are similar,and the maximum values all appeared near the pier.Within the side span loading range,the impact of concentrated loading on the non-loading side is smaller at low speed,while the line load loading has an impact on the entire bridge deck.Within the mid-span loading range,the maximum displacement response values of different loading modes have similar envelope curves,but the peak value under concentrated force loading is significantly larger than that under line load loading.The results can provide a certain reference for the inspection and maintenance of this project and similar bridge projects during their service life.