重载铁路20 m超低高度预应力混凝土梁桥动载试验研究

摘要

为了掌握桥梁结构在动荷载作用下的工作和受力状态,评估桥梁在正常使用状态下的运营性能,详细阐述西干渠中桥20 m超低高度预应力混凝土梁的动载试验全过程.采用大准铁路运营货列作为测试对象,上、下行运营货列空、重车在试验桥梁区段以指定6个速度档通过.每个速度试验车不少于3趟.车辆编组分5 000吨和10 000吨,空、重车最高行车速度80 km/h.测出桥梁结构的跨中横向、竖向振幅,跨中横向、竖向加速度和支座横向、竖向位移.试验结果表明,超低高度预应力混凝土梁承载能力和刚度满足设计要求.所得结论为桥梁加固、桥梁限速等提供依据.%In order to grasp the operation and force state of the bridge structure under dynamic loads,and to evaluate the operation performance of the bridge in the normal service condition,the whole process of dynamic load test of 20 m ultra-low height prestressed concrete beam on West Main Canal Bridge is elaborated.The operating freight train on Datong-Zhunge'er Railway is taken as the test object.The up and down operation of the freight train of empty and loaded vehicle are required to run at 6 speed gears in the section of test bridge.And the test vehicle at each speed is not less than 3.The vehicle marshalling consists of 5000 tons and 10000 tons,and the maximum driving speed of both empty and loaded vehicles is 80 km/h.The transverse and vertical amplitude of the bridge structure,the lateral and vertical acceleration of the span,and the lateral and vertical displacement of the support are measured.The test results show that the load-bearing capacity and stiffness of the ultra-low height prestressed concrete beam meet the design requirements.The conclusion provides the basis for the reinforcement and speed limit of the bridge.