Combined rock cross-cut coal uncovering method

Abstract

The invention discloses a combined rock cross-cut coal uncovering method which is particularly suitable for quick rock cross-cut coal uncovering of outburst dangerous coal seams in underground coal mines. When a cross cut is tunneled to be at a vertical distance of 10 m from coal seams, a drill site is directly constructed in the cross cut; the coal seams are constructed and holes are drilled in the drill site; the drill holes are arranged at intervals by slotting drill holes and general drill holes; the uniform pressure relief of coal bodies is realized through the combined arrangement of the slotting drill holes and the general drill holes. After the drilling operation is finished, pipes are connected for extraction and drainage to reduce the gas content and the gas potential in the coal seams. After the gas extraction is qualified, the slotting drill holes are used as slurry injecting drill holes to inject cement mortar in the coal bodies for strengthening the coal bodies, so that the combination of slotting pressure relief and reinforcement is realized. Under the condition of guaranteeing safe coal uncovering, through the adoption of the method, the outburst removing engineering amount can be reduced by 30-40%, the gas extraction time and the coal uncovering period can be shortened, and the safe coal uncovering speed is increased by 40-50%.

Description

technical field [0001] The invention relates to a combined stone gate coal uncovering method, in particular to a safe and quick coal uncovering method suitable for protruding dangerous coal seams underground in coal mines. Background technique [0002] Coal and gas outburst (hereinafter referred to as outburst) is a dynamic phenomenon in which the gas-containing coal body in a coal mine is suddenly thrown into the mining space in a very short period of time. It is one of the most serious disasters in coal mine production. Outburst often occurs in the process of uncovering coal in Shimen. At present, it is generally believed that the outburst is the result of the comprehensive effect of in-situ stress, gas pressure and coal-rock strength. Scholars at home and abroad have proposed many outburst-preventing methods for uncovering coal in Shimen based on the outburst mechanism. Measures such as blasting and hydraulic slotting mainly include measures such as metal skeleton and gr...

AI Technical Summary

Problems solved by technology

Measures such as hydraulic slotting can effectively relieve the ground stress and gas pressure, but at the same time destroy the integrity of the coal body and reduce the overall strength of the coal body; grouting reinforcement can effectively improve the strength of the coal body, but the cement mortar can only spread in the cracks. The crack opening is small, the diffusion radius is limited, and the resistance along the way is large, and the grouting pressure is high (>10MPa), which increases the difficulty of sealing holes and the operation risk

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