Influence Mechanism Of Mining Disturbance On Slope Stability In Surface Coal Mine

Aiming at the effect on slope safety of surface coal mine brought from dynamic changes of dump capacity and underground mining, this paper applies surface mining technology, geostatistics, mine rock mechanics, numerical simulation and field tests, and studies the effect originated from mining disturbance comprehensively. Based on geostatistics theory, physical and mechanical parameters of rock mass are taken as regionalized variables, and the regionalized model of physical and mechanical properties is established. Through the rock mechanics experiments, mechanical indexes of dump floor and waste material are analyzed, and semi-variant function model of physical and mechanical properties of rock mass is established. Then the spatial and temporal distribution is educed. According to the characteristic of surface coal mine with inclined orebody, the stability numerical simulation model of dump is established, then the stability changing rule of open pit stope with dynamic diversification of mining height is educed. Based on the setting rule of surface mine dump, the coupling model of dump capacity and slope stability is established, then the changing rule of dump stability with dynamic capacit diversification is revealed, so is strata displacement rule with defferent external load. Aiming at the effect of external dump on surface mine stope slope, the coupling mechanics model of external and stope is established. After analyzed the stress distribution of stress field superposition formed by external dump and surface mine stope, the effect of it on stope slope is studied. According to the dynamic coupling relationship between the formation of surface coal mine dump and surface mining and stripping, the loading stress diversification with different dump capacity, mining parameters and mining program is analyzed. Then the optimization method of mining parameters and dumping program beneficial to releasing the loading stress of dump slope stability. According to the actual situation, the sliding style possibly occurring in diluted materials is forecasted, and the working modes and operation parameters of dumper are studied. According to the analysis of the mined slope affected by open-pit and underground mining, girder model of mined slope is built. Based on the stress state of the girder, the distortion is analyzed and the range of arch grown out of girder distortion is obtained. By analyzing the sinking range originated from broken roof strata, the mathematical models of stability coefficient of slope under open-underground mining and the most safety mining depth are established, then the mechanical mechanism of deformation is educed. Though numerical simulation of FLAC3D, the displacement rule of overlying strata and the influence originated from the width of coal pillar protecting slope on strata subsiding range are studied. Then the slope displacement monitoring system is established to protect the slope and surface coal mine production. The case studies of Xiaolongtan and Heidaigou Surface Coal Mines are carried out to improve the effectiveness and correctness of the thesis'research contents, methods and conclusions which will be significant to enriching and developing the theory and method for surface mining.