| Pillar is an important structural unit of determining the stope stability, it plays a supporting role in the mined area. It not only maintains the stability of roof and surrounding rock, but also have great potential of improving the recovery rate of ore. At present, owning to mining of "take one every other one" and lag filling work, the stability of pillars is increasingly outstanding in Dongguashan Copper Mine. Aiming at the problem of pillar stability under high stress in deep well of Dongguashan Copper Mine, using the methods of theoretical analysis, numerical simulation and field measurement, the paper carries out the research as follows:(1)Based on two free facing pillar which is formed after the deep stope mining in Dongguashan Copper Mine, applying damage-fracture mechanics Principle, it is analyzed that the damage mechanism and evolution of the rock pillar mass fracture under high stress in the deep well; Using the dynamic Rock dynamic damage software RFPA2D, the failure process of two free facing pillar is simulated, which provides the basis for predicting the Stability of two free facing pillar under high pressure.(2) Using simulation software Midas/GTS, a numerical simulation model is set up. The simulation of "take one every other one" recovery process of Dongguashan Copper is carried out. The changes of stress, displacement, plastic zone of the pillar and surrounding rock are revealed. Also, the possible dangerous positions of pillar and surrounding rock during mining are analyzed.(3) Using 3D laser detection (CMS) technology and 3D modeling technique, 3D shape of goaf and pillar are obtained rapidly and accurately. It verify visually numerical simulation results of the pillar stability of two free facing pillar and mining of "take one every other one",(4) According to the result of 3D laser detection, based on software Surpac, visual calculation of the collapse volume and accurate delineation of the pillar collapse scope are realized. The collapse volume and the volume of restant ore in the goaf are calculated accurately. (5) Causes of the pillar collapse are analyzed. Specific measures of dealing the pillar collapse are put forward .And according to problems of the pillar stability after mining of "take one every other one" in Dongguashan Copper, specific preventive measures are provided.Practice has proved that the above methods open up a new way for the analysis and prediction of the pillar stability under high stress in deep well. It is of an important practical significance for guiding safe and efficient exploitation of mines... |
