大准线黄河特大桥(96+132+96)m钢桁梁检定试验研究

Test Study for Rating (96+132+96)m Steel Truss Girder of Datong-Zhungeer Yellow River Super-long Bridge

大准线是运煤重载铁路,运营列车轴重25 t,万吨编组,最高行车速度80 km/h。线路上的黄河特大桥钢桁梁为(96+132+96)m三跨连续式、无竖杆刚性桁梁柔性拱组合体系结构。2011年对黄河特大桥钢桁梁进行了静动载试验,并将本次试验结果与以前测试结果和仿真计算结果进行了对比。静载试验结果表明:钢桁梁在中-活载和恒载作用下,上下游2片主桁受力较均匀;桥梁承载力和竖向刚度符合设计标准,满足使用要求。动载试验表明:桥梁自振频率与成桥时基本一致,说明运营至今桥梁整体性能和技术状态变化较小;实测桥梁杆件动力响应较小,动力性能良好。

Datong-Zhungeer Railway is a heavy-haul line dedicated to coal transportation.The train axle load is 25 t,the freight train marshalling is 10 000 t and train maximum running speed is 80 km/h.The steel truss girder of Datong-Zhungeer Yellow River Super-long Bridge is(96+132+96)m three spans continuous truss,which is a composite system of steel truss without vertical bars and f lexible arch.A comprehensive static and dynamic rating test was accomplished in 2011.The test data were analyzed and compared with that of previous test and f inite element analysis results.The results show that,in the aspect of static performance,under the China railway standard live load and dead load,the stress of the two main trusses on the direction of the lower reach and upper reach of Yellow river are uniform and well distributed.The bearing capacity and vertical stiffness of the bridge are in accordance with design standards and meet application requirements.In the aspect of dynamic performance,the natural frequency of bridge is the same as that of 20 years ago.So there is small change in bridge performance and its technical state.The dynamic stress of steel continuous truss girder is small.The bridge has a good dynamic behavior.