Study On The Mechanism Of Grouting Reinforcement Of Weak Medium Filling Cracks

In recent years, Grouting method has more than 200 years of history, in tunnels, mines, foundation treatment and other fields are widely used, due to the reinforcement of weak geological effect is remarkable, its long-term application prospect is also very broad, will bring enormous economic benefits and social benefits. However, with grouting engineering practice of vigorous development is opposite, the grouting theory progress is quite slow, difficult to keep up with the pace of the development of engineering practice, resulting in lack of theoretical guidance of grouting engineering, grouting efficiency is low, resulting in a huge waste of slurry, and grouting is quite empirical and blindness, it is difficult to establish a set of grouting theory and practice of various comprehensive grouting system, the grouting theory there are still large developing space.In order to change the current development model test is difficult to take into account the current situation of study on diffusion of grouting and reinforcement effect, the author designed the experimental table of plane fissure filling with soft medium, with dozens of groups of experiments of slurry the weak plane fissure filling medium diffusion form, describing the diffusion rule and grouting reinforcement mechanism. The main innovations are as follows:ger space for development.(1) design the weak medium model test system for grouting, design soft filling materials plane fracture conditions of experimental design;(2) the concept of the effective diffusion zone of the slurry in the weak medium is proposed and studied.;(3) of the cement slurry diffusion process, analyzed the grout diffusion for the diffusion theory, deduced the whole slurry diffusion process of grouting pressure and grout diffusion distance relationship;(4) the influence of weak medium conditions on grouting reinforcement effect was studied. Analysis of the grouting after, weak medium permeability, anti shear changes and rules of the, forming a weak medium filling the application of new technology.Through the numerical simulation in engineering application and study based on finite element simulation during grouting slurry in the surrounding rock mass flow and groundwater along the tunnel seepage caused by surface subsidence. The main conclusions are as follows:(1) in the process of grouting, grouting hole location in the middle of the slurry to ring to flow; away from the wall at 2 m head the fastest increase; from the wall 2m-4m at rock slurry liquid concentration is higher.(2) after grouting, the surface subsidence decreased obviously. The maximum vertical displacement under the condition of non grouting is 6.94mm, the maximum vertical displacement of the grouting is 2.75mm. After grouting, the head loss of surrounding rock and the seepage velocity of groundwater are obviously decreased..(3) groundwater along the tunnel seepage caused head loss arising from the surface settling tank was approximately Gaussian distribution, intermediate values, the values at the two ends is small. The slope of about 1 times hole diameter is the largest in the middle distance of the center line.By participating in the grouting project team of Shandong University, a phase blocking main research results are as follows:(1) for the tunnel roof extremely broken and weak situation, under the premise of ensuring the safety of roadway found the roof high confined water at least drilling induced displacement calculation basis.(2) in the roadway in hot and humid environment, use the whole space transient electromagnetic and geological radar detection technology to accurately detect the roadway roof concentrated rich waterfront and fracture zone development scope, as the exact layout of grouting holes, the implementation of security grouting provides the basis.(3) to explore the roadway surrounding rock seepage field evolution; real-time monitoring through the field of surrounding rock deformation, effects of grouting on the stability of surrounding rock of roadway are obtained.(4) in the tunnel roof extremely broken and rich under the condition of strong water safety grouting technology is studied, the pressure relief namely deep drainage, shallow layer grouting reinforcement process. Not only guarantee the roadway safety and grouting after grouting, completely meets the need of water plugging.(5) the application of C-CL in the roadway reinforcement and water shutoff is studied.. Aiming at the poor quality of 2# unloading of coal bunker chamber arch body, fracture development status is investigated using the C-CL grouting material, not only to ensure grouting reinforcement of security, but also improve the seed setting rate of grouting material and reached good grouting water plugging effect.(6) the use of hollow screw grouting for the first time is used in the hydraulic grouting and water-grouting..