铁路桥梁支座更换前后运营性能影响研究

Study on the Impact of Operational Performance before and after Railway Bridge Bearing Replacement

摘要: 随着我国经济发展对铁路运输能力要求不断提高，既有铁路扩能运输改造进程不断推进，不断提高的列车轴重给既有铁路桥梁带来了一些新的病害，尤其是支座出现了耐久性退化、承载力不足以及失效的病害，并且大多数情况下均采用更换支座的方式来改善重载铁路桥梁的运营性能。本文以某铁路桥梁的病害板式橡胶支座为研究对象，采用顶升法将病害板式橡胶支座更换为球形钢支座，并对更换前后铁路桥梁的跨中横竖向振幅及横竖向加速度等参数进行了对比，研究了支座病害对铁路桥梁运营性能的影响。研究结果表明：钢支座的横向限位功能较板式橡胶支座更为优越；板式橡胶支座更换为钢支座后，支座的横向位移有所减小，同时桥跨主梁的跨中横向振幅及横向加速度均有不同程度的降幅；支座更换对主梁竖向振幅及竖向加速度等竖向动力参数影响较小。

Abstract: As China’s economic development imposes higher demands on railway transportation capacity, the process of capacity expansion and transportation renovation for existing railways continues to advance. The increasing axle loads of trains have introduced new challenges to existing railway bridges, particularly in the form of bearing issues such as durability degradation, insufficient load-bearing capacity, and functional failure. In most cases, bearing replacement is adopted to improve the operational performance of heavy-haul railway bridges. This study focuses on a specific railway bridge where the deteriorated plate rubber bearings were replaced with spherical steel bearings using the jack-up method. A comparative analysis was conducted on parameters such as mid-span transverse and vertical amplitudes and accelerations before and after the replacement to investigate the impact of bearing defects on the operational performance of railway bridges. The results indicate that the lateral restraint function of steel bearings is superior to that of plate rubber bearings. After replacing the plate rubber bearings with steel bearings, the lateral displacement of the bearings decreased, and the mid-span transverse amplitude and acceleration of the main girder were reduced to varying degrees. However, the bearing replacement had minimal impact on vertical dynamic parameters such as vertical amplitude and acceleration of the main girder.