Mining Voids Distribution And Grouting Reinforcement Treatment

The voids in the goaf are one of the incentives of secondary subsidence, coal spontaneous combustion, accumulation of harmful gases and mine water inrush.This paper takes the balanced structure of the secondary rock mass of the broken rock mass as the main research object, uses the means of theoretical analysis to put forward the view that the overburden structure of the old goaf remains stable when the coal pillar and the key block are stable. Based on the characteristics of rock formation, the height of the collapse zone and the fracture zone under different conditions is deduced, so that the predicted height of the fracture zone under the condition of arbitrary lithology can be obtained.Finally, the height of the fracture zone is determined.In the compression of crushing rock mass, if the axial load is small,the increase of axial strain is mainly caused by the adjustment of the broken rock position. If the axial load is large, the axial strain increases,and the reason is that the broken rock further broken into small particle size under stress concentration slides into the gap. Water plays a role in accelerating the deformation of the broken rock. On the one hand,the water acts as a lubricant between the broken rocks, which facilitates the adjustment of the particle position in the broken rock. On the other hand, the water acts as a porters of small pieces of broken crushed rock ,which accelerates the small particles sliding and filling the gap between the large particle size gravel.The similarity simulation study determines the distribution law of the voids, while the crushing rock mass compression experiment determines the porosity of the caving zone, and the fracturing zone has little or no grouting gap due to the closing effect. The collapse zone is divided into irregular caving belt and regular collapse zone, so the grouting volume only calculates the void volume of the regular caving zone and the irregular caving zone is reasonable. The height of the collapse zone is similar to that of the simulation. The height of the irregular caving zone is 0.915?0.975 times of the thickness of the recovery. The porosity is determined by the porosity determined by the crushing rock compression experiment. The pore volume is expected.Combined with the goaf grouting site by drilling grouting detection,detection, detection, stone hole TV bearing performance test for detection of goaf grouting effect, test results show that: after grouting,the data processing center of 1# building site suitable for construction.