Ground Surface Settlement Control Technology For Large-span Tunnelling Under Railway Region

As the urban rail transit are build expansible at a large scale,the new Tunnels line underpassing the railway is more and more and the crossing mutual influence between them becomes inevitabaly.the settlement and deformation of the existing railway roadbed is caused during the new tunnel construction underpassing.Therefore it is very import that studying on the settlement and deformation of the new tunnel construction and controlling underpassing the controlling criteria of the existing railway station is very necessary.Based on the data collecting and summarization that the mined tunnel underpass existing railway,studied settlement deformation regularity,analysised the deformation index of the existing railway,come forward about the control principle based on vertical deviation by smoothness of the existing railway,related safety operation rules,combined with railway safty rule,made the controlling criteria.Relying on the xi’an railway station tunneling project,this paper studied shallow tunnel tunnel construction control technology in the soft soil.Smulated excavation process different construction tunnelling methods and different ways of reinforcement in advance through model test,measuring the stress change of the surrounding rock,surface subsidence,lining stress,explored the rule of the lining stress rule,surface subsidence rule.Finally,come up with ground surface settlement control method for xi’an tunneling project under railway region in soft soil.Based on the xi’an railway station tunneling project,used numerical simulation,simulated tunnel excavation process,analyzed the process of surface subsidence,the rule of lining stress, put forward constructive suggestions for the design and construction of xi’an railway station subway tunnel.