| Since 1966, the low vibration track has been developed by Switzerland and laid in the Boetberg tunnel in Switzerland. For its characteristics of flexibility, less maintenance and so on, it is laid widely in tunnels and subway lines at home and abroad. The extra-long tunnel Wu-Shao-Ling, an import part of the Lanzhou-xinjiang line also chose the low vibration track. Since the operation of the tunnel in 2006, varying degrees of injuries occurs in some parts affected by environmental or other factors. Aiming injuries, effective maintenance measures are carried out timely. This article focuses on injuries and maintenance measures of Wu-Shao-Ling tunnel. The main research work and details are as follows:Firstly, introduce the application of the twin-block ballastless track and the low vibration track at home and abroad. Then introduce the general situation about main structures, ancillary equipment, the topography and the geological structure of Wu-Shao-Ling tunnel. Detail the low vibration track design and injury situations in the tunnel. Discuss appropriate maintenance measures for different injuries.Influence of hanging empty of inverted arch backfill layer on track bed was analyzed. An analysis model based on 3D finite element method was established. Simulate the hanging empty part. As seen from the force and the displacement of the track bed with different range of hanging empty injury. When the range of hanging empty is greater than 3.7m, the tensile stress of the bottom of track bed will be greater than the standard value of concrete axial tensile strength-the concrete cracks. When the range of hanging empty along longitudinal direction of the inverted arch backfill layer reaches to 3.4m, cracks occur at surface of the track bed. When the range of hanging empty along longitudinal direction of the inverted arch backfill layer reaches to 5.366m, vertical displacement of rail will be greater than 3mm, which will have a greater impact on driving comfort and safety. |
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