A method for gob-side entry retention of advanced deep-hole pre-splitting roof

Abstract

The invention relates to the field of underground mining in coal mines, in particular to a method for retaining roadways along gobs. In this invention, drilling is carried out on the upper roof along the pre-crack line of the roof in the roadway in front of the coal mining face. The upper part of the drilling is filled with energy-concentrating charges within a certain range, and the lower part of the drilling is not filled with charges within a certain range. The blasting is carried out before the advanced pressure on the working face, and the rock formation at the upper part of the drilling hole is pre-split by blasting, and the lower rock formation is kept intact to ensure the safety of the construction space. After the working face is pushed through, the fast-hardening and high-strength concrete roadside support wall is built by pumping concrete to fill the mold bag technology. Under the action of the roof pressure, the roadside support wall cuts off the unpre-cracked roadway lower roof, and the roof is artificially controlled. Breaking position and fall height. The invention can promote the fall of the gob gangue and fill the gob in time, and the goaf gangue bears the pressure of the overlying roof; reduces the length of the suspended roof of the gob; thereby reducing the deformation and pressure of the gob-side roadway. Purpose.

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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