Study on Fully Mechanized Top Coal Caving Slicing Mining Technology of Ultra Thick Seam Under Water Body

Base on the analysis on the mining and topography and other condition of the Chenjiagou Mine in Huating Mining Area,the high pressurized water input in the upward deep hole,built-in gas transportation,double end sealing,constant pressure leakage measuring equipment were selected for the observation of the water flow crack zone height in the overburden strata of No.3201 and No.3202 fully mechanized top coal caving mining faces in the slices of thick seam of Chenjiagou Mine.The max cracking and mining ratio observed was 11.39.in combination with the numerical simulation analysis and the surface ground crack observation results,a formula to calculate the coal and rock pillar thickness for safety mining under the river was analyzed and provided for the fully mechanized top coal caving mining in slice of the ultra thick seam in Chenjiagou Mine.The study achievements provided the reliable basis to the safety mining under the water body in Huating Mining Area.