Water prevention technology of shallow-buried depth and super large mining height fully-mechanized mining face passing surface channel flow

There are mainly two aspects of the influence of surface ditch flow on the mining of shallow-buried and super-large mining height fully mechanized working faces. First, the surface water seeps into the gob through the mining fissures, which threatens the production safety. The second is that the formation of surface gully flow makes the bedrock in the area flowing through is thin, the underground mining pressure is not obvious, and the hard coal body has adverse effects on production. The above two types of issues seem to be unrelated, but they usually exist at the same time, and become the difficult problem for safe and efficient mining. This paper takes the No.12402 working face of Shangwan Coal Mine in Shendong Mining Area as an example, the research was carried out to studythe ground surface collapse and other situations in this environment. On this basis, the shallow-buried and super-large working face worked through the surface ditches and water prevention measures, including the surface drainage comprehensive treatment measures such as dredging the surface water, back filling the collapsed riverbeds, and raising the dam to ensure the smooth flow of the river and improve the seepage resistance of the riverbed, so as to achieve the purpose of water prevention and control. In addition, through key technologies such as underground aquifer detection and release, the threat of water gushing from the aquifer is eliminated. By increasing the drainage capacity of the working face and roadway, the problem of water gushing at the working face is effectively solved. At the same time, the purpose of reducing the water accumulation in the gob was achieved without adjusting the slope of the floor. Through the above water control measures in the well, the water pressure can be decomposed and prevented in time and space, and a better water control effect can be achieved. In order to ensure the safe production of the working face under the ditch, combined with the thin bedrock and shallow-buried underground pressure, numerical simulation, field test and other methods are used to propose a method of hydraulic fracturing to weaken the strength of the coal body to solve the strength of the hard coal body. Through numerical simulation, the fracturing parameters were determined, the fracturing design scheme was optimized, and the actual production was continuously improved, which reduced coal energy consumption and achieved the effects of protecting equipment and removing dust. © 2021 Meitan Kexun Jishu/Coal Science and Technology (Peking). All rights reserve.