Study On The Law And Influence Factors Of Ground Movement And Deformation Due To Underground Mining

Exploiting the mine resources could guarantee the energy and material demands of the country, promoting the development of the country economy and the modern industry. But the mining subsidence resulting from the underground mining on the other hand has an adverse impact on human living environment, restricting the sustainable development of the economy and the society. The direct impact of the mining subsidence is ruining the ground surface. With the increase of the mining scale, the ground movement and deformation becomes worse. Although all levels of government and organizations have pay much attention on prevention and treatment, the issue has yet to be solved. The main reason is that the theory for mining subsidence is not complete and the mechanism and the regularity of ground movement and deformation are still unclear. Therefore, understanding the movement and deformation of the ground surface as well as its influence factors is a must so as to reduce the adverse impacts of the underground mining.This work is supported by the project"Long-term stability of rock and law of surface subsidence inducing by the deep exploitation"(No. 04207520070527) from najing qixiashan deposit, combing the field observation, theoretical analysis, and numerical simulations. The main conclusions are summarized as follows:â‘ The three-dimensional models for the ground movement and deformation are established based on the stochastic medium theory for different exploiting conditions. The movement and deformation of ground surface for two different conditions are investigated.â‘¡The ground surface displacement monitoring of mining areas is introduced briefly. Based on the back analysis of the data, the parameters for the ground movement are obtained, and the prediction models are established. The models are validated by comparing the predictive results with the measured data. Based on the real situation, the impacts of mining depth, mining thickness, depth-thickness-ratio, main influencing angle, mining width are investigated, providing the guidelines for the treatment.â‘¢General triaxial tests and field geological survey are performed to obtain the mechanical parameters for rock stratum and filling body. The three dimensional models are established based on the finite difference software FLAC3D, with which the variation of the displacement for the conventional mining and back filling mining are predicted. The simulation results, theoretically predictive results, and the measured results are compared, and it is revealed that random medium theory and numerical simulation can well predict the movement of ground surface.â‘£The impacts on ground movement of elastic modulus of filling body, passion ratio, internal friction angle and cohesive forces are investigated by combing the back analysis, stochastic medium theory and numerical simulations. It is shown from numerical results that: the impacts of elastic modulus is greatest, followed by internal friction angle, the cohesive forces and passion ratio have little impact. The results providing the scientific basis for designing and optimizing the parameters of the filling body .