高速铁路隧道无砟轨道上拱整治技术研究

近年来,我国交通建设迅猛发展,复杂艰险山区铁路隧道工程规模庞大,为降低维修养护成本,满足高速铁路运营安全及乘客舒适度的需要,隧道内采用大量的无砟轨道结构,但仰拱施工仍然延续以前的施工生产模式,时有隧底积水、虚砟、欠挖等施工质量缺陷,导致无砟轨道结构开裂、上拱、下沉等病害,严重影响列车运营安全。依托某运营高速铁路隧道,为解决无砟轨道结构上拱的病害,采用现场调查、物探及钻探验证的方法,查明仰拱及填充厚度不足、隧底积水是导致病害段轨道几何位移的主要原因;根据病害段实际情况,采取限速45km/h、锚杆加固隧道边墙、切断钢轨及道床板(保留支承层)后,设置短轨并利用两端既有的道床板支承层及仰拱填充架设钢垫梁,分段拆换仰拱、填充及支承层,分段现浇道床板,恢复轨道结构,实现隧底病害的彻底整治。

Research on Treatment Technology for Ballastless Track Upwarp of High-speed Railway Tunnels

In recent years, China's transportation construction has been developing rapidly, and railway tunnels in complex and difficult mountainous areas are huge in scale. In order to reduce maintenance cost and meet the needs of safety and comfort, a large number of ballastless track structures are used in tunnels. However, the construction of inverted arch still employs the previous production mode and such quality defects occur in tunnels as water accumulation at the bottom, loose ballast, under excavation and so on, resulting in cracking, upwarp, subsidence and other defects in the ballastless track structure and seriously affecting the safety of train operation. Based on the actual situation of a high-speed railway tunnel in service, this paper uses on-site investigation, geophysical prospecting and drilling to solve the problem of upwarp in ballastless track structure. It's found out that the main causes of track displacement in defected section are insufficient thickness of inverted arch and water accumulation at the bottom. According to the actual situation of the defected section, measures are taken, such as setting up speed limit of 45 km/h, reinforcing side wall by anchors and cutting off the track and slab(maintaining support layer) to install short track and set up steel cushion beam based on the existing track slabs and inverted arches at both ends. The inverted arch, fillings and supporting layers are then replaced in sections, slabs are casted in situ and the track structure is restored. Thus, the tunnel bottom defects are thoroughly remedied.