Numerical Simulation And Analysis Of Stress Distribution In Backfilled Stopes

As an important factor in the layout of the domestic economy and the nationaleconomy, mineral resource is affecting the process of industrialization in China andthe world. Though it brings enormous economic benefits, there are also seriousdamage to ecological environment in mining issues, such as ground subsidence,groundwater pollution.It is necessary to meet the required national production and life, and to hold theidea of sustainable development, which the mining industry has put forward higherrequirements. Use mine waste mined areas fill mining method for controlling regionalgeological stability and reduce the incidence of mine is important, not only can fullyrecover mineral resources, but also to achieve the purpose of the surface withoutdamaging the environment, in line with sustainable development strategicrequirements.In order to protect itself and the surrounding rock stability of backfill, backfillreasonable to design methods, processes and materials, study the stress distributioninside the stope backfill is quite necessary. Currently, stope backfill, whether backfillmaterial for high-tech or conventional backfill materials, cement is an important partof the filling compound. It is understood that, when using cemented backfill, minefilling nearly half of the total costs of mining production costs, the cost of cementbinder which accounted for almost half the cost of filling.On the basis of Natural Science Foundation of my supervisor application,Research focuses on stress distribution in underground stope, the use of numericalsimulations to verify the existence of internal stress arching stope, and accurateanalysis of the effects of various physical parameters on the stress distribution andstress arching effect. The following researches of this thesis are performed:(1) Analytical solution has been the primary means of studying stress distribution,has verified the existence of the arching in backfilled stopes. On the basis thetheoretical model of the analysis method to establish a numerical model in this paper.The use of numerical simulation software FLAC3D numerical analysis, verified thereliability of numerical simulation by comparing the two methods. Ultimately it isvalidated by numerical simulation that arching is present in backfilled stope.(2) Since the analytical method has been included in some relatively strongassumptions and simplifications, numerical simulation can completely avoid this kindof problem, numerical simulation results obtained show Marston theoryunderestimates the vertical stress and horizontal stress in backfilled stopes, thenanalyze the reason and found some limitations in the application process Marstontheory.(3) The numerical simulation results analysis that, the number of backfill has asignificant impact on stress distribution in backfilled stopes, with the increase in thenumber of backfill, the smaller the vertical stress the same depth.(4) Study on vertical stresses in backfilled stopes by applying the arching method,changing the width of the backfilled stopes, the friction angle, cohesion physical andmechanical parameters, elastic modulus, Poisson’s ratio of filling material and accessits impact on arch shape and the distribution of stresses.