Study On The Effect Of Grouting Reinforcement And Control Parameters In Deep Buried Coal-rock Mass

There are a large number of fissures, joints and cleats in deep buried coal-rock mass under the effect of high ground stress and geological activities. In the process of tunneling and mining, the deformation and failure of coal-rock mass will increase by the stress redistribution and the mining pressure and influence the roadway stability and working face mining safety. Grouting reinforcement technique is commonly used in geotechnical engineering and can effectively improve the object physical and mechanical parameters which can improve the self-bearing capacity of rock and soil. Based on the background of Zhao Zhuang coal mine, the permeability and fracturing grouting reinforcement of breaking and fracture coal-rock were studied. The performance of grouting materials, reinforcing effect, grouting parameters influencing factors and permeability and fracturing grouting interaction mechanism were studied through the experimental study, theoretical analysis, numerical simulation and field test methods. The several following results were obtained.(1)The rheological property, stability and setting and hardening properties of ordinary cement, fly ash cement and superfine cement were studied through laboratory test. The rheology, stone rate and 2h water separating proportion of various types of cement under different water cement ratio and time were gotten. The complete stress-strain curves, elastic modulus, strength variations of the grouts stone were analyzed. According to the fitting curves of superfine cement, the strength empirical formula of 3d, 7d and 28 d curing age were gained. The concretion specimen failure modes were summed up and the causes were analyzed.(2)The uniaxial compressive strength,residual strength, tensile strength, c and Ï… etc were gotten through the laboratory test of the basic physical and mechanical tests of the coal-rock mass and mudstone samples. Based on the slurry material test and physical and mechanical tests, the grouting reinforcement test of broken and fractured rock mass was carried out,and the stress-strain curves of the grouting reinforcement under the conditions of different broken degree and slurry strength were gotten. The strength, elastic modulus, deformation and failure mode of grouting reinforced specimen were analyzed. The influence law of broken degree and slurry strength to grouting reinforcement was gotten, the reasonable slurry strength parameters of coal-rock mass and mudstone grouting were obtained.(3)The diffusion rule and control parameters on the single fracture were studied based on Newton fluid motion. The grouting pressure value of splitting failure under the slurry pressure and stress are calculated based on the elasticity theory. The grouting pressure for crack expansion and the crack extension length were calculated based on the analysis of damage and fracture mechanics theory. The fracturing grouting pressure of the roadway and working face were calculated by the Abaqus under the different buried depth, horizontal tectonic stress field and roadway size. The crack range of grouting hole without grouting pressure was analyzed according to the calculation results. The relationship between fracturing grouting pressure and expansion pressure of surrounding rock were analyzed under different conditions.(4)According to the tendency to the spalling and roof falling of mining working face and deformation and failure of auxiliary tunnel in Zhao Zhuang Mine, the reasonable grouting control parameters of working face and roadway were calculated by the Abaqus; The grouting reinforcement technical scheme of roadway and working face was put forward.