Research On Instability Mechanism Of Mining Area Under Influence Of Typical Fault In The Gypsum Mine

Gypsum, as the important nonmetallic mineral resource, is playing more and more important role in economic development. With the increasing range of mining stope, the geological structure near the stope has been activated that have a significant threat to the stability mining area. In extreme cases, it can lead to instability of mined-out area and cause heavy casualties and property losses. But the research on the instability mechanism of the gypsum stope under the influence of the fault which is the typical representative of bad geological tectonics is still insufficient. So, it has the positive meaning to study the instability mechanism of the mining area under under the influence of the fault.According to the method based on combination of the theoretical analysis and case investigation and numerical simulation and laboratory experiments and establish the bond-slip-Kelvlin brittleness model, to analysis the modes of fault failure and mining instability, the paper puts forward an idea to study the rule of mining area under the influence of regional structure and the mode of suface subsidence in the gypsum mine, relying on the research subject <Research and Control on Rule of Mining Damage from Goaf in the Gypsum Mine> of Province Natural Science Foundation of Hubei.The main research results are as follows:Firstly, to establish the surface subsidence basin model that is caused by mining affected by fault based on the key stratum theory and the elastic thin slab theory, get the calculated formula of maximum sinkage, the morphological parameters in the vertical direction, the subsidence center offset under the influence of the fault.Second, get the rules of gypsum mining area displacement, the plastic zone expansion and the surface subsidence by simulating the different advance distance of the working face in the gypsum mining area. According to the above-mentioned regularities, get the instability mechanism of the mining area under the influence of fault in the gypsum mine which is that first the roof telos staying away the fault produced the tensile destruction and the roof falled by delivering to the central roof, next the ground on the mining are area subsidence. At the same time, get the rule of the stress and displacement changes near the mining area by simulation studying the different dip angles of a specific.Finally, it is that mining instability phenomenon and its mechanism in the HD gypsum mine is analyzed by theoretical calculation and FLAC3 D based on the rule of mining damage in the normal faults' hanging wall of the gypsum mine. To find out fault damage is or not a major cause of instability in mining area by calculating the roof stress and checking the limit span of bord and the pillar reliability. To study the buckling collapse accident fault, the stress and displacement of roof and pillar change state in HD gypsum mine that are by comparing and analysising many kinds of multi-loading numerical model. Considering the formation and development of gypsum mine mining dynamic disasters, to deep research fault- mining damage model and put forward a surface subsidence basin model that is caused by mining affected by fault, that are simply validated through the numerical simulation results. And, to provide the theory basis for the management of mining damage accident in the HD gypsum mine and proposed a new angle to study the rule of mining damage under the influence of regional structure in the underground gypsum mine.