Rock Pressure Activity Regularly Due to Underground Mining of the Deep Phosphorus Ore with Several Inclination by Similar Material Simulating Experiment

摘要

On basis of the geology mining condition of the deep ore bodies of north mining area of Two-hang hau of Jingning mine of Yunnan phosphate group Co. Ltd, the strata behavior regularity of the working-face in the process of underground mining was systematic research with the dip angle of twenty degreen and fity degren. The result showed that: (1) after the underground mining of the phosphorus ore, the stress bearing of the excavation phosphate rock transfer to the surrounding rock mass, the initial rock stress was disturbated, this process has been extend outward with the expansion of the excavation space, deformation and failure problems has been happened, and the new stress equilibrium will be formed in the last, mined-out area was formed after ore body's excavation, near the gob roof area formated stress unloading area, stress formed in certain areas ahead of the stope roof pressurization district, with the excavation of the ore bodies, the roof stress pressurization district dynamic forward position, the pressurization district scope and degree of pressure also decreases as the excavation scope of mined-out area space and gradually increase, and is located in the rear area of the stope deformation of old goaf roof damage fracture belt and the abscission zone was gradually closed. and in the mined-out area space range after reaching a certain size tends to be stable, then recovery section stress and to support its upper part of the gravity of overburden rock. （2）As the orebody dip Angle increases, the same excavation space range, goaf in front of the maximum stress concentration factor was reduced, unloading of overburden rock and concentrated area of the whole range becamed smaller, the rock pressure activity becamed easing as a whole. Relevant results can provide Yunnan phosphate group co., LTD., subordinate to the mines and mining under similar conditions of phosphate rock mountain project to provide certain reference basis.