Technical Research On Exploiting Unstable Coal Seam With Compound Roof

The proportion of low-angle dip and inclined seam is increasing gradually with the mining level extending in Da'anshan coal mine. The complex geological conditions and structures cause the coal seam irregular. The thin coal , thick coal, and no coal district appear alternately, which brings the questions of the working management, the safe production, and the resources effective recycle. According to geological structure situation, surrounding rock characteristic and coal seam characteristic of Da'anshan coal mine, the methods of theory analysis, numerical simulation, the on-the-spot mine pressure monitoring and mining experiment have been used to research the technology of exploiting the low-angle dip and unstable coal seam with compound roof. The reasonable mining method, tunnel support parameters, the support design and technical parameters of work face have been determined. The mine pressure monitoring and the support quantity analyzing system software has been developed, then the activity rule of country rock and emergence rule of the mine pressure has been analyzed, which provides the important basis for the coal exploiting under the similar condition. Through the practice, the support design parameters of the work face and tunnel meet the demand of safe production. Da'anshan coal mine obtained better economic benefit in exploiting the low-angle dip unstable coal seam with compound roof by the excavation method of single prop, joint roof beam, blasting fall coal, and roof whole caving.