Research On The Theory Of Grouting Diffusion And Reinforcement In Layered Media Based On Physical Simulation Test

In recent years, the economic and social construction of China develop vigorously. Infrastructure construction, especially the field of transport construction is accelerating dramatically. Because of the complicated geological conditions as well as the construction of a large number of tunnels, the construction of the tunnel often construct through the adverse geological conditions such as sand, faults, karst, which will easily induced water and mud outburst disaster in construction. Analysising by the information, water and mud outburst disasters occur frequently and do great damage. The disaster cause construction equipment destroyed, a large number of casualties, severe economic lossed and even schedule delayed, rerouting or abandoned tunnel site, restricts the economic development and social stability severely.Fault fracture zone in rich water is one of the main geological disasters sources which induced water and mud outburst disaster in tunnel. The treatment of such disasters is usually grouting. However, due to the complex geological environment, the invisibility of the medium injected, uncertainties of grouting diffusion, grouting material and equipment dropping behind, the grouting technology can not meet the needs of grouting. Therefore, this paper use the methods of analyzing and derivation the theory, model test and COMSOL numerical simulation software to explore grouting mechanism comprehensively that grout into multilayer injected medium in hydrodynamic conditions, and the mechanism of the interface of different stratified medium. Specific results are as follows.(1) Through research and analysis of hydrological and geological conditions and tectonic mechanism with F2 fault fracture zone in Yonglian tunnel, we drew reason of the water and mud outburst reason disasters. Seen F2 fault fracture zone as geological background, we establish three kinds of engineering geological model of governance which are advance curtain grouting, temporary disaster curtain grouting, after disaster curtain grouting.(2) Establish soil-rock layered medium grouting model, and carry out the layered grouting diffusion theory. We expand theoretical analysis and formula derivation about four kinds of grouting diffusion form, such as soil-rock interface cracking, interface splitting channel extension, soil media compaction splitting, gravel media penetration packing.(3) To explore the ligation through the fault fracture zone in Yonglian tunnel and the mountain, we developed a fault fracture zone simulation test system that grouting material and injected media conditions are similar to the geological conditions and construction methods in Yonglian tunnel. We learn that the media reinforcement by grouting mainly contain filling, compaction and split by test. By the effect of the three forms, the permeability of the injected medium is decreasing, injected ability is continuously weakening, and intensity continue to increase. Reinforcement on different media layer interface is mainly connection between the two forms of wide pulp pulse and fine pulse pulp.(4) Analyzing the date of shear capacity, soil pressure and osmotic pressure by testing, we study the effects of strength, porosity, permeability, and the ability to be injected by grouting. Further more, we analyze serous diffusion rules of layered grouting process from the local to the whole.(5) Established numerical models of layered media landfill composite grout diffusion, and quoted Darcy flow equation. By numerical simulation COMSOL, simulated different conditions of the whole process of serous diffusion. Simulated the whole process of serous diffusion with stratified landfill for the transverse and vertical. Summarized the variation in the serous diffusion process with the pressure field, the volume fraction, and the fixed interface pressure. Presented advantages penetrate and advantage splitting phenomenon. Hydrodynamic environment is introduced in simulation process, and we summarized the impact of serous proliferation by hydrodynamic conditions in different working conditions through the volume fraction regularity of serous diffusion.(6) Propose "continuous drilling, deep drilling and segmented on high pressure" comprehensive grouting technology to governance water and mud outburst in Yong Lin tunnel, and inspection grouting effect by P-Q-T curve and inspection analysis. The control of grouting quality overall achieve the design requirements. The governance played a larger role in improving reinforcement effect of surrounding rocks.