Gobside entry retention method without coal pillars for self-elimination of filling walls

Abstract

A non-coal-pillar gob-side entry retaining method having filling-wall self-elimination comprises the following steps: during the exploitation of an upper-section coalface (1), pumping a high-water material into a flexible mold bag (3) along the edge of a goaf (2), forming a roadside filling-wall (4) by construction, and disposing a breather pipe (6) in the filling-wall in advance; and during the exploitation of a lower-section coalface (7), cutting the flexible mold bag (3) behind the coalface, and injecting carbon dioxide into the breather pipe after the exploitation is completed, so that a carbonization reaction occurs on the filling-wall, and the filling-wall is broken and decomposed, so that the self-elimination of the roadside wall is achieved. In the method, during the gob-side entry retaining service period, the high-supporting performance of a high-water material roadside wall is fully come into play; the self-elimination of the filling-wall can be achieved after the gob-side entry retention is abandoned, accordingly the stress concentration generated by the leftover of the filling-wall is prevented, the effect of full pressure relief on upper and lower adjacent coal beds is achieved, and the method has a positive effect on mining space maintenance, gas extraction and dynamic disaster prevention and control.

Description

technical field [0001] The invention relates to a gob-side entry retention technology, in particular to a coal-pillar-free gob-side entry retention method which is suitable for the field of shaft support engineering and is self-eliminating for filling walls. Background technique [0002] Under the condition of short-distance coal seam group occurrence, the mining of one coal seam will inevitably affect other coal seams, and the concentrated stress formed in the upper and lower rock strata by the residual coal pillars of the first coal seam is one of the most critical adverse effects. Mining stress concentration restricts mine production layout, mining space maintenance, and pressure relief gas control, often leading to serious consequences such as roof collapse, rock burst, and gas outburst. Gobside entry retention without coal pillars can greatly reduce the degree of this impact and eliminate the dynamic disasters caused by the concentrated stress of coal pillars. [0003]...

AI Technical Summary

Problems solved by technology

However, there is still a lack of a method of gob-side entry retention without coal pillars and rock pillars. The existing gob-side entry method largely limits the range of pressure relief for the mining of protective layers in close-distance coal seam groups, hindering Development of Continuous Pressure Relief Mining Technology

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