Key Technology Of Railway Tunnel Construction In Inter-granular And Shallow Buried Section Of Carbonaceous Mudstone And Sandstone

The stability of surrounding rock in shallow buried fractured strata has been a hot research topic in geotechnical engineering.Based on the quality of the ground sleeve valve tube grouting method used in the construction scheme of the shallow buried section of the Carbon Mudstone sandstone inter-beds in the actual project,based on the engineering geological conditions of the actual tunnel engineering and the engineering geological problems appearing in it,the theory and technology of grouting reinforcement for the surrounding rock of the shallow buried fracture section are combined with the FLAC finite element method.Differential software is used to simulate the excavation condition,and the key technology of railway tunnel construction is studied for the carbonaceous mudstone sandstone inter-bedded shallow buried section.The main conclusions and results are as follows:(1)On the basis of the detailed description of the engineering geological conditions on the site of the project,the engineering geological problems existing in the shallow buried section of the onions tunnel are analyzed.The effectiveness of the site sleeve valve tube grouting and consolidation measures is verified by analyzing the monitoring data after the measures are taken to reinforce the tunnel.(2)On the basis of the analysis of the engineering properties of the carbonaceous mudstone sandstone stratum,and based on the main understanding and consensus of the grouting reinforcement at home and abroad,the principle of the sleeve valve tube grouting used in this project is studied,and the construction sequence of the field sleeve valve tube grouting method is elaborated in more detail,and the whole seepage of the sleeve valve tube grouting method is analyzed.It is divided into four stages of filling-extrusion-splitting and re infiltration.By analyzing the working mechanism of each stage of the permeation process,the mechanism of strengthening the rock mass in the shallow fractured section is studied.(3)Based on the FLAC finite difference software,the stress characteristics,deformation and displacement laws of the surrounding rock of the shallow buried section of the tunnel under different working conditions are analyzed in detail.The results show that the surrounding rock stress of the surrounding rock of shallow broken section is reduced,and the surrounding rock stress is reduced,and the plastic zone is easily developed and connected,causing the large deformation of the vertical direction,causing the hidden danger to the construction,and providing the basis and reference for the construction of the tunnel and the advance surface reinforcement.