Analysis And Solution On The Influence Of Tunnel Through Railway Bridge

With the development of social economy,the railway development in China is very fast.At the same time,the road network planning is improving and the density is increasing.Road network is arranged in a crisscross pattern,which make the railroads inevitably have to pass under the bridge opening of existing road or railway bridges after construction.The tunnel construction has made great progress recently.However,no matter what method is used it will inevitably cause deformation and movement of the surrounding soil in the tunneling process,which affects the stability and safety of adjacent bridge foundation and bridge structure.In railway engineering,the safety influence on the super bridge structure and the selection of technical measures in construction process have become the difficult problems which needs to be solved.In this paper,the corresponding numerical simulation research is carried out,the main contents include:(1)According to the project profile,Guangzhou-Dongguan-Shenzhen inter-city track Taiping tunnel under the Guangzhou-Shenzhen-Hong Kong Passenger Dedicated Line Humen Bridge 22 and 23 pier of the 72 m continuous beam,the proposed mining method for excavation,construction process will have some influence on the settlement and deformation of the bridge pile foundation and the road surface.(2)Through the study of similar projects in the country and the relevant data to determine the Humen Bridge settlement deformation limit.The initial stress field of the super-bridge and the surrounding foundation of the tunnel is calculated,and the initial stress field with high accuracy is provided for the tunnel before the excavation.Then,the whole process of excavation and excavation of the whole tunnel is simulated,and the influence law and extent of tunnel excavation on bridge pile foundation are studied.Then,the time-domain irregularized samples of low-disturbance spectrum conversion in Germany are used as the excitation of high-speed train lines,and the dynamic load simulation is carried out.The influence of train vibration on the deformation of bridge foundation is analyzed,and the deformation in dynamic load calculation is demonstrated by time-history curve.At the same time,the simulation results show that the sudden impact of the excavation process on the bridge foundation is studied.Finally,the stability of the face is analyzed by the model calculation to prevent the sudden occurrence before the excavation,and the deformation characteristics before the excavation are analyzed.Through the study,it is concluded that the settlement of the bridge foundation caused by the excavation of the Taiping tunnel satisfies the relevant specification and does not affect the platform of the Humen station.(3)According to the results of numerical simulation analysis and the study of similar projects in China,the countermeasures of reinforcement protection and monitoring control in the construction of Taiping tunnel are put forward.