Study On Stability And Reinforcement Of Surrounding Rock Of Loess Tunnel Under Water Soil Interaction

In the fourteenth five year plan,it is proposed to speed up the construction of transportation power,and tunnel is an important part of transportation construction.However,due to the special topography and geological conditions of most tunnels,there are many unfavorable geological phenomena.Most of the coal transportation railways to be built are located in the loess area.In order to explore the surrounding rock stability and reinforcement method of loess tunnel under water soil interaction,the following three aspects are studied in this paper(1)Taking a coal transportation railway tunnel in Shaanxi Province as the engineering background,the paper studies the properties of geotechnical seepage,concludes that the main object of seepage research is gravity water,summarizes the prediction method of tunnel water inflow,and selects the rainfall infiltration method to determine the tunnel water inflow according to the relevant references.Based on terzagi effective stress principle and Darcy’s law,combined with Biot consolidation equation,material constitutive equation and equilibrium equation,The governing equations of fluid structure interaction are obtained.(2)Using FLAC3 D numerical simulation software,the Mohr Coulomb model is selected to endow the model with water soil coupling effect.In order to clarify the variation law of deformation at different initial water levels and different key points,the initial water levels are selected as 10 m,20m and 30 m respectively.Through the comparative analysis of pore water pressure,surrounding rock stress,strain and lining stress under each initial water level,the stability of surrounding rock of loess tunnel under water soil interaction is studied.(3)The collected field monitoring data are analyzed and processed,and the hyperbolic function regression analysis model is selected for regression analysis,so as to obtain the temporal variation curve of surrounding rock displacement.Through the simulation of the proposed reinforcement measures,the grouting reinforcement and the application of Φ Through the comparative analysis of pore water pressure,surrounding rock stress,strain and lining stress of 28 diameter main reinforcement,it is concluded that grouting reinforcement is a more reasonable scheme.This paper has 80 figures,21 tables and 70 references.