Study On The Influence Of The Third Series Of Water-rich Sand Mudstone On The Tunnel And The Pre-reinforcement Measures

Due to the complex nature of the engineering encountered in the tunnel construction industry in recent years,the surrounding rock is susceptible to disturbance,and the deformation is large after excavation,and the lithology is complicated,which has plagued the construction problem of the tunnel.In order to ensure the safety of the tunnel construction process,the pre-reinforcement measures are usually adopted to pre-strengthen the front rock in front of the face.In China,the pre-reinforcement and small-pipe grouting pre-reinforcement measures are used as the tunnel through the rock fracture zone and the weak stratum Common pre-reinforcement measures play an important role in tunneling through poor geology.In this paper,based on the Aimin Tunnel of " Haerbin–Mudanjiang High-Speed Railway ",the deformation characteristics of the surrounding rock of the Tertiary water-bearing sand-mudstone and the tunnel crossing through the third-line rich mineral rock are analyzed by means of theoretical analysis,monitoring and numerical simulation.Section of the pre-reinforcement measures for comparative analysis,the main contents of the paper are as follows:(1)Based on the actual engineering situation of Aimin tunnel,this paper summarizes the previous engineering experience and summarizes the pre-reinforcement measures of domestic and foreign tunnels,and analyzes the reinforcement mechanism of different pre-reinforcement measures.According to the monitoring situation in the actual construction of the field deformation,the deformation characteristics of the surrounding rock of the rich water sand and shale landslide are summarized.(2)According to the monitoring results of Aimin tunnel,the deformation of the surrounding rock and the supporting structure of the supporting structure under the rich water and sandstone strata are analyzed,and the stress and surrounding rock of the supporting structure of the tunnel under the rich water and sandstone strata are summarized The law of deformation.The simulation results show that the numerical simulation results are basically the same as the actual monitoring results.In the measured values,the lining support structure is larger and some of the steel frames are yielding,and it is necessary to carry out the pre-reinforcement measures.To ensure the safety of construction.(3)The numerical simulation of tube prefall and small pipe is carried out,and the numerical simulation results are compared with those of the tunnel without pre-reinforcement measures.In the simulation of grouting reinforcement area,The simulation results show that the pressure of the overburden rock after the prefabrication of the pipe shed is far and the reinforcement zone is strengthened,and the reinforcement area is better than that of the reinforcement area in the construction area.The smaller the force is smaller,the lower surface of the face is smaller and the convergence value of the tunnel is smaller,and the convergence value of the tunnel is smaller.(4)Combining field monitoring with theoretical analysis and numerical simulation,the reinforcement effect of pipe roof and small pipe pre-reinforcement measures in the water-bearing sand-shale formation is evaluated,and it is proved that the reinforcement measures are adopted in combination with the three-Dredging method can be very good to suppress the deformation of the surrounding rock to ensure the safety of tunnel construction,similar projects have some reference value.