| Because the roadway is a principle channel of underground mining production, its drivage and maintenance have an important proportion of mining cost and influence on production and construction of coal mine. In rock engineering such as mining and underground tunnelling engineering, roadway drivage and maintenance are influenced of many factors.Due to complex factors such as mining dynamics, tectonics, arrangement, prop, design of coal pillar etc, during process of driving and mining, roadway is deformed and failed. It resulted to influence on regular production of mine.When product-geological environment is complex, arrangement of roadway is unreasonable or prop isn’t sufficient, because high ratio of failure generation, one has to maintain and repair continuously, it causes not only high cost of prop but very difficulty of coal mining and serious danger of stable production. As the depth of mining is increasing, many problems may be arisen such as big displacement, high in-situ stress, difficult propping, failure of prop, repeating investment and many times of repeat repairing. The initial stress field is one of important factors to influence on roadway stability.With increment of depth, orientation of tectonic stress is more obvious and the difference between two horizontal stresses is greater, therefore it induces many difficulties in constructing and mining including damage, failure of prop and instability of roadway.In this paper, from the viewpoint of complex geological condition, using numerical simulation, studied influence of anisotropy and fracture on the stress, displacement and failure of roadway in different lateral pressures and suggested its failure mechanism.The main contents conducted in the paper are as follow.1. Based on theory of generalized planar strain problem, studied the law of stress-displacement variation around roadway in condition of three dimension stresses. Also using COMSOL3D multiphysics software, analyzed an influence of angle between axe of roadway and direction of maximum horizontal stress on stability and Failure mode of roadway and determined its rational arrangement in tectonic stress field.2. For the problem of relation between initial stress field and failure mode of roadway, used RFPA software to simulate the failing process of unfractured rock roadway and analyze how homogeneity, compression-tension ratio and strength criteria influence on the result. From these, it was studied the relation between initial stress field and failure mode of roadway. And the related experiments were compared with simulation result to prove its correctness.3. For the stability problem of fractured rock roadway, based on the function of normal and exponential distribution of Monte Carlo method, the2D structural plane was produced and used RFPA2D software to simulate an influence of structural plane on the stability of roadway.Thus analyzed how distribution type, angle and filling material of fracture influence on failure mode of roadway4. In order to analyze an influence of anisotropy on roadway stability, it was suggested a new method where no needs complex elastic matrix in partial coordinate system and used two coordinate systems in COMSOL software to briefly consider the direction of anisotropic material. Based on the stress-strain relation of complex material and Hoffman strength criteria, it studied an anisotropic roadway problem in two and three dimensions.And used COMSOL3D software to simulate how an anisotropic angle influences on the stress, displacement and failure mode around roadway in condition of different lateral pressures.5. For stability of roadway at Yanzhou coal mine of Shandong, simulated how working face influence on roadway in miming process and suggested the rational design of rock bolting. |
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