Modeling And Field Test Study On Lateral Deformation Grouting Reinforcement Of Metro Tunnel In Zhengzhou Area

With the construction of urbanization and the continuous development of Metro Tunnel engineering,more and more overlying projects are being built in the vicinity of the existing subway tunnels.In the course of construction,the overload of the pile and the excavation and unloading of the foundation pit are bound to cause the deformation of the existing subway tunnel,which will affect the safe operation of the subway tunnel.Moreover,the deformation of the subway tunnel is also related to its engineering geological conditions,such as the properties of the geotechnical body around the tunnel and its existing groundwater conditions.At present,the deformation control of subway tunnel based on silt area is the first case in Zhengzhou,and most of the research mainly focuses on the deformation control of subway tunnel in soft soil area.Therefore,for the deformation control of metro tunnel in silt area,through the field "micro disturbance" grouting test and grouting reinforcement theory model,the control tunnel deformation problem is analyzed,so as to provide reference for similar engineering practice.The underground transportation project of Zhengzhou Comprehensive Transportation Hub(East Square)crosses the shield tunnel of the metro and makes the East Square north-south interchange through three communication channels(1#,2#,3#).Based on elastic-plastic mechanics and the existing theory of slurry permeability and diffusion,this paper establishes a mathematical model of grouting reinforcement effect,and conducts the following analysis and Research on the reinforcement effect of side grouting of tunnel:(1)Based on the existing grouting theory model,it is studied how to improve the model so that the model is suitable for the lateral deformation control of metro tunnels in silt areas.(2)According to the existing theory of slurry hole expansion,establish a mathematical model of slurry column diffusion,and derive the numerical formula of the effect of grouting on tunnel segments;by changing the spacing of grouting holes,the distance between grouting pipe and segment Its influence on the convergence deformation of the tunnel.(3)Combining the actual engineering conditions,the largest section of the convergence deformation below the contact channel is selected as the research object.According to the field test data,the calculated values of the mathematical model are compared and analyzed,and the appropriate grouting parameters are selected to grout the tunnel.Effectively control the deformation of the grouting parameters to provide reference for similar projects in the future.