Leading deep hole pre-splitting roof gob-side entry retaining method

Abstract

The invention relates to the field of underground mining of coal mines and particularly relates to a leading deep hole pre-splitting roof gob-side entry retaining method. The method disclosed by the invention comprises the following steps: drilling on an upper roof along a roof pre-splitting line in a roadway in front of a coal face, filling shaped charge at the upper part of the drill hole in a certain range, not filling the charge at the lower part of the drill hole in a certain range, tamping with stemming, detonating before a leading pressure of the face, blasting and pre-splitting rock stratum at a charged part at the upper part of the drill hole, wherein the lower rock stratum is kept complete, and construction space safety is ensured. Quick-hardening and high-strength concrete roadway supporting walls are built after face pushing by adopting a technology for filling pump concrete in a mold bag, non-split lower roadway roof is cut off by the roadway supporting walls under the action of a roof pressure, and the roof breakage position and falling height can be manually controlled. According to the method disclosed by the invention, gangue falling in a goaf can be promoted, thegoaf can be filled in time, and the overlying roof pressure can be borne by the gangue in the goaf; the suspended length of the roof in the goaf is reduced, so that the aim of reducing the deformationand pressure of the gob-side entry retaining roadway is achieved.

Description

technical field [0001] The invention relates to the field of underground mining in coal mines, in particular to a method for retaining roadways along gobs. Background technique [0002] Gob-side retaining is a mining method that cancels the coal pillar protection roadway during underground mining of coal mines. Gob-side retaining can cancel the coal pillar, reduce the amount of roadway excavation, improve the resource recovery rate, and eliminate the residual coal pillar stress in the upper coal seam Concentration, changing the ventilation mode of the working face, reducing gas accumulation at the working face, etc. Therefore, the gob-side entry retaining has great technical advantages and economic significance. [0003] The conventional method of existing gob-side entry retaining is to construct the roadside support behind the hydraulic support, rely on the roadside support to support the roadway roof and cut off the roof in the goaf. However, under the conditions of high ...

AI Technical Summary

Problems solved by technology

However, under the conditions of high mining height or high roof strength, the roadside support cannot cut off the side roof of the goaf, or can only cut off a part of the lower roof, resulting in insufficient roof fall in the goaf and excessively suspended roof. Big, old top spins and sinks

The overhang of the old roof is too large, which increases the roof pressure of the gob-side retaining, and the rotation and sinking of the old roof increases the deformation of the gob-side retaining. The excessive deformation exceeds the allowable deformation of the roadside support, resulting in protection damage, resulting in difficulty in maintaining gob-side entry, or even failure

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