Study On Formation Law Of Ground Fissures Under Extremely Thick Igneous Rock Exploitation In Tiefa Mining Area

Ground fissure is a phenomenon of geological disasters that caused by the mining subsidence of surface movement and deformation. This paper uses the studying method of spot investigation and numerical simulation. Aiming at the complex phenomena of the ground movement the deformation and fracture that caused by thick igneous rock distribution in Tiefa mining area. Analyze the theory characteristics which used in mining subsidence such as key stratum theory, equilibrium arch theory, of the thin plate theory. Then use equilibrium arch theory and establish the numerical simulation calculations model of extremely thick igneous rock and the equilibrium arch have none or one or two intersections. Theoretically deduce the appearing law of ground fissures. And the finite element model is established by using ANSYS numerical simulation software. Simulation the stress distribution relationship between the ground fissures and giant Thick Igneous Rock that overlying rocks under the igneous rock. After comparative with the spot investigation of the ground fissures happened place it can be analyzed and conclude that:the theoretical derivation completely anatomize the ground fissure's formed site and numerical simulation calculations fully consistent with the ground fissures forming site of Tiefa mining area. The results show that:the model which used in the mine exploitation is very important. The ground fissures which caused by the extremely thick igneous rock's (or other hard rock's) fracture the model can exploratory application in the situation that prevention and expected the mine disaster. The model also has a practical significance in disaster prevention.