Research On Settlement Prediction And Control Of The Passenger Dedicated Line During The Under-Passing Of The Shield Tunnel Construction

It’s a challenging task to under-passing the settlement demanding Passenger Dedicated Line for shield tunnel construction.Along with the development and progress of China’s high-speed railway technology, a trail version of the high-speed rail is enacted, which provides for the settlement limits to guide the design and construction. However, the specification only consider the single factors during the high-speed rail construction, which is not perfect, and there are also a few similar projects case to under-passing the built line for reference.Based on the Northern Guangzhou subway station~Huacheng Road subway station interval shield tunnel project, the track slab settlement rule is studied during the shield tunnel under-passing the Wuhan-Guangzhou Passenger Line, based on the forecast of the settlement limits, numerical simulations is used to determine the vertical settlement and cross-sectional differential settlement of the process, the main work are as follows:(1) The Passenger Dedicated Line settlement standard during the shield tunnel construction is initially proposed as10mm.(2) Without carrying out the MJS method to reinforce stratum, in consideration of pseudo-dynamic and static load, research track slab settlement law during the under-passing, the final settlement value achieves58.7mm,which is used as a contrast to conditions with the reinforcement one, and prove the necessity of reinforcement;(3) Analysis the reinforcement process and the track slab settlement law after the reinforcement of MJS method, taking into account the pseudo-dynamic, static load, compare reinforce or not as a whole analysis result, the final max settlement value reduced to only9.6mm;(4) Analysis the transverse uneven settlement value of track slab under3kinds of different situations which shows that the max uneven settlement is1mm:(5) By curve fitting based on the settlement trough, the article proves that the preliminary standard during the tunnel construction under-passing is reasonable;(6) Against the analysis conclusions, some of the more practical and beneficial security measures are proposed to control subgrade settlement, in order to provide a reference for similar construction.