Building Of Tunnel Excavation Model In Jointed Rock Mass And Research On Deformation Law Of Surrounding Rock Based On TSP Information

With the rapid development of the economy,the high-speed rail as a Chinese business card is also booming.Tunnel is the main solution for high-speed rail to cross mountainous region,and its proportion of high-speed rail has also gradually increased,in which extra-long tunnel usually become the control project of high-speed rail.In the construction of tunnels across mountains,it is inevitable to pass through jointed rock masses,and it is important to ensure the safety and stability of construction.Therefore,advanced geological prediction become an important part of construction.Based on a tunnel in the north of China as the engineering background,this paper selected the mileage DK031 + 710 ? DK031 + 780 as the analysis section.Based on the TSP advanced geological forecast data and the design parameter of tunnel,numerical simulation calculation was used as the analysis method,and FLAC 3D finite difference simulation software was used as a tool,to conduct the research of the influence of the existence of joints in the rock mass on the stability of the tunnel construction.The main work and results are as follows:(1)The principle of TSP advanced geological forecast was analyzed,and the feasibility of estimating the spatial distribution of joints using the TSP advanced geological forecast reflective surface data was verified.The occurrence of the joint of the analysis section of this tunnel was derived from this(2)Arranged the on-site monitoring data of this tunnel,according to the conditions of the construction site,analyzed the deformation law of the lining when the tunnel crossing the joint in actual engineering.(3)Compared and analyzed the differences between Mohr-Coulomb constitutive model and Ubiquitous-Joint constitutive model,arranged the geological data and design parameters of this tunnel,determined the boundary conditions and material parameters of the numerical model.FLAC 3D finite difference simulation software was used and Ubiquitous-Joint constitutive model was selected to simulating the analysis section of this tunnel.(4)By using numerical simulation,the deformation law of surrounding rocks and linings,the deformation law of tunnel working face,the mechanical characteristics of support structure and the construction response of the tunnel when multiple joints interact with each other were analyzed.By setting the working conditions without small lead pipes structural elements and the working conditions without groutingreinforcement,the effect of advanced leading conduit and grouting reinforcement on the physical and mechanical characteristics of jointed rock mass were analyzed.(5)Verified accuracy of the numerical simulation results based on the comparison with the actual monitoring data of the project.