基于健康监测的武汉军山长江大桥重车过桥响应分析

Response Analysis of Wuhan Junshan Changjiang River Bridge Under Passage of Heavy Vehicles Based on Health Monitoring

武汉军山长江大桥为主跨460m双塔双索面钢箱梁斜拉桥,2011年安装了健康监测系统。该桥通行多为重车,并时有超载现象出现。为了解重车过桥结构性能,评判重载对结构的影响程度,基于该桥上安装的健康监测系统,对2辆载重178t的重车先后通过该桥的主梁位移、桥塔偏位、主梁应力、索力进行了全程采集,并与有限元计算值、阈值进行对比分析。分析结果表明:桥梁空载状态和卸载状态下桥塔残余变形以及主梁残余变形和残余应力均较小,卸载后斜拉索振动幅值恢复正常,结构处于弹性状态,性能良好;重车过桥结构响应均在活载计算包络曲线内,重载对结构的影响很小,结构无损伤发生;结构响应实测值与计算值吻合较好。

Wuhan Junshan Changjiang River with double pylons, double cable planes and with Bridge is a steel box girder cable-stayed bridge a main of 460 m and in 2011, the health monito- ring system was installed on the bridge. The vehicles passing the bridge are mostly the heavy ve- hicles and from time to time, the overload vehicles may appear on the bridge. To understand the structural performance of the bridge under passage of the heavy vehicles and to judge the degrees of influence of the heavy load on the structure, the whole process data of the main girder displace- ment, pylon offsetting, main girder stress and the stay cable forces of the bridge at the time 2 sets of the 178 t heavy vehicles passed the bridge in succession were acquired based on the health monitoring system and the data were analyzed and compared to the finite element calculation val＋ ues and the threshold values. The results of the analysis suggest that the residual deformation of the pylons and the residual deformation and residual stress of the main girder of the bridge in the state of empty load and unloading are little. After the bridge is unloaded, the vibration amplitude values of the stay cables return to normal, the structure is in the elastic state and the structural performance is good. The structural responses of the bridge under passage of the heavy vehicles are within the range of the live load calculation envelope curves, the influence of the heavy load on the bridge is little, the structure has no damage and the measured values of the structural re- sponses are well agreeable with the calculated ones.