Surrounding Rock Stable Analysis Of Mine And Application Study About Regular Hexagon Mining Method With Filling

Metal mine resources was decreased in our country. The current metal ore mainlylocated in complex geological conditions. The geological disasters increased year byyear. In order to guarantee the stability of surrounding rock and improve the efficiencyof mining, the regular hexagonal route filling mining method was analyzed. Thedistribution of displacement field, stress field and plastic zone of single room andmulti-room were analyzed with the theoretical method and finite element method. Thesafety factor was defined to a stability estimating index. The regular hexagonalapproach filling mining method was applied to iron ore projects of Gujiatai located inLaiwu, which verified the rationality and feasibility of regular hexagonal route. Themain work can be summarized as follows：(1) The analytical method was used to solve surrounding rock stress of regularhexagonal section. The mapping function was used to obtain mapping function ofregular hexagonal section under the condition of elastic from exterior domain of the unitcircle to general shape section. Comparing the numerical simulation results withcalculation results, the analytical solutions are more reasonable. The stress distributionis analyzed on the sides of ore room. FLAC3D numerical simulation analysis showedthat, the stress of both sides of stope rome changed from tension stress to compressivestress with the increase of surrounding rock grade.(2) Considering the numerical simulation of the regular hexagon route filling miningmethod was calculated, which considered the buried depth, surrounding rock grade andbackfill ratio. Rock roof displacement and safety factor was increased with the burieddepth deepening, surrounding rock grade and backfill ratio decreases. Stress transferredto two sides of room stope gradually. The area of plastic zone gradually increased.(3) According to the orthogonal experiment design method, nine test schemes weredesigned, which considered the buried depth, surrounding rock grade and backfill ratio.The roof maximum settlement and the area of plastic zone is defined as the valuationindex of stability of mining surrounding rock. Results showed that the surrounding rock grade was the most important influencing factor, and the buried depth was the next.(4) The stability of surrounding rock are analyzed, which considered the geologicalconditions at the present and high geo-stress conditions of Gujiatai iron ore mining inthe future with the same area and width height ratio of regular hexagonal andrectangular route mining filling method. Results showed that the area of stressconcentration mainly distributed in the ore pillar mining at first, and it transferred to twosides of the surrounding rock of the ore pillar lately. The regular hexagonal route werebetter than rectangular route by comparing the roof displacement and area of stressconcentration. This advantage is more obvious in high geo-stress environment.