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| Aanlysis of Influence of Misalignment of Drainage Ditch on Static and Dynamic Response of Low Vibration Track in Tunnel |
| REN Juan - juan 1 , LI Xiao 1 , ZHAO Hua - wei 1 , NI Yue - feng 1 , CHEN Li - jie2 |
| (1. MOE Key Laboratory of High - speed Railway Engineering, Southwest Jiaotong University, Chengdu， Sichuan 610031，China; 2. Ganzhou - Longyan Double Track Railways LLC. of Nanchang Railway Bureau， Longyan， Fujian 364000, China) |
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Abstract Abstract ： Research purposes ： Owing to its good noise and vibration reduction effect，low vibration track ( LVT) is widely used in tunnel and subways. In general， in order to facilitate tunnel drainage， a drainage ditch is located in inverted arch of track center line. Due to construction error and other factors, there might be a big misalignment between track center line and central line of drainage ditch. Under certain conditions, misalignment of drainage ditch will cause damage of cover plate as well as contact loss underneath slab，and then influence driving safety. The control index of contact loss underneath slab is put forward by analyzing the influence of misalignment of drainage ditch on the static mechanical performance of track，for instance，rail displacement and cover plate stress，as well as influence of contact loss underneath slab on the dynamic response of vehicle acceleration, rate of wheel load reduction and so on, which can provide theoretical reference for maintenance of contact loss underneath slab of LVT in tunnel. Research conclusions:(1) Misalignment of drainage ditch has limited influence on the static mechanical performance of track. When misalignment between supporting block and drainage ditch reaches to 25 cm，the maximum stress of cover plate is 0. 25 MPa. (2) When length of contact loss underneath slab less than 0. 55 m, contact loss underneath slab has negligible influence on vehicle acceleration, wheel — rail force and rate of wheel load reduction. (3) When the length of contact loss underneath slab exceeds 0. 55 m，vehicle acceleration，wheel - rail force and rate of wheel load reduction increased significantly, which can affect the driving comfort and safety; it is recommended that the length of contact loss underneath slab due to misalignment of drainage ditch should be kept below 0.55 m. (4) The research achievements can provide theoretical reference for maintenance of LVT in tunnel.
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Received: 03 December 2015
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2016, Vol. 33 
