Blocking method of insidious karst collapse pillar of deep coal mining layer

Abstract

The invention discloses a blocking method of an insidious karst collapse pillar of a deep coal mining layer. Grouting governing is conducted, grouting governing adopts a three-stage filling grouting method through drill holes to conduct grouting, a water-stopping plug is formed on a base plate water-containing layer, and the water-stopping plug is complete and relatively water insulation. Grouting through the three-stage filling grouting method comprises the following steps that (1), an aggregate water-blocking body is formed through aggregate filling; (2), reinforcing grouting is conducted through filling of cement/coal ash to form a mixed water-blocking body; and (3) the grouting is filled with cement to form a cement water-blocking body. Through the technical scheme of the three-stage filling grouting method provided by the invention, the collapse pillar is quickly blocked, the residual water gushing quantity of the mining working face is less than 5 m<3>/h, it is guaranteed that an explored water gushing channel and pre-existing fracture are subjected to high-pressure grouting, and an effective water-blocking plug is formed on a target layer, so that the effect of water gushing blocking of the target layer and ordovician limestone water-containing layers below the target layer is achieved, and water holding safe mining is completed.

Description

technical field [0001] The invention belongs to the field of coal mining, and more specifically, the invention relates to a method for plugging hidden karst collapse columns in deep mining coal seams. Background technique [0002] In the process of deep mining of coal seams in coal mining, hidden large-scale vertical water-conducting structures, so-called collapse columns, are easily induced by large-scale water inrush disasters under the influence of high water pressure and mining disturbance; As the depth increases, the fissures in the new floor are developed, resulting in activation of the fault, and the thickness of the effective water-resisting layer of the floor becomes smaller. The dynamic supply of ash participates in the water inrush, and the risk of water damage control increases. The existing technology is to prevent and control the grouting by drilling holes to the bottom plate. The grouting uses normal pressure to inject cement slurry. This method is not only di...

AI Technical Summary

Problems solved by technology

[0002] In the process of deep mining of coal seams in coal mining, hidden large-scale vertical water-conducting structures, so-called collapse columns, are easily induced by large-scale water inrush disasters under the influence of high water pressure and mining disturbance; As the depth increases, the fissures in the new floor are developed, resulting in activation of the fault, and the thickness of the effective water-resisting layer of the floor becomes smaller. The dynamic supply of ash participates in the water inrush, and the risk of water damage control increases. The existing technology is to prevent and control the grouting by drilling holes to the bottom plate. The grouting uses normal pressure to inject cement slurry. This method is not only difficult for cement to reach the bottom plate but also very easy At the same time, the phenomenon of cement slurry loss may also occur when encountering water gushing channels and original cracks during the grouting process. It is difficult to ensure the blocking of water inrush from the target layer and the Austrian ash aquifer below, and to complete water conservation and safe mining. A large amount of cement slurry use, increased production costs

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