| It's inevitably that tunnel excavation will lead to ground movement and deformation, the impact will be large especially when the tunnel is shallow and large span. Beijing-Zhuhai double-tracked lines Changsha-Xiangtan expressway LiJiaChong tunnel is large span and all long shallow-buried, and a 500kV power transmission tower is located at top of it, the risk of tunnel construction was very high. How to ensure the safety of the high-voltage power transmission iron tower was the biggest problem need to solve during tunnel construction.The interaction and characteristics between tunnel construction and the tower was studied though three-dimensional numerical simulation, so as to give theoretical support to field construction, and timely feedback to service construction by real-time monitoring in the construction. The main research contents as fellows:(1) The risk of tunnel construction was studied on the basis of field research and paper study, and several projects of tower reinforcement and tunnel construction are given for choice in order to reduce hazard.(2) The interaction and characteristics between tunnel construction and the tower is studied, and the effects of different reinforce and construction methods are evaluated though three-dimensional numerical simulation of the whole tunnel construction process using ABAQUS after establish hill-tunnel-tower model. At last, a feasibility plan was put forward for construction.(3) The change and characteristics of surrounding rock deformation, stress of tunnel support structure, tower settlement, Tower internal forces were reflected by real-time monitoring during Li-Jiachong tunnel construction, and the safe conditions of the tunnel and tower were affaimed. Meanwhile, the comparative analysis was carried out between calculational results and geodesic results, to verify whether the Numerical calculated result is valid and reliable or not.(4) After comprehensive analysis the field monitor and numerical simulation results, the interaction and characteristics between tunnel construction and the high-voltage transmission tower were summarized, which enrich the content in tunnel and adjacent structures interaction research, it's also guidance for similar projects. |
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