Coal face top plate water-rich gravel layer drilling and grouting method

Abstract

The invention discloses a coal face top plate water-rich gravel layer drilling and grouting method. According to the method, ground construction drilling is adopted, vertical downward drilling is constructed from the ground and goes deep to 2-3 m above the gravel layer, a casing pipe is arranged in a drilled hole, and a ring gap between the casing pipe and the drilled hole is filled with cement for fixing; and downward descending advancing type drilling-grouting-hole penetrating cyclic grouting is adopted from the terminal end of the casing pipe, the end hole depth is a bed rock layer, and after the end hole grouting pressure reaches the grouting finishing standard, the hole is sealed through pure cement paste, and grouting is finished. By means of the coal face top plate water-rich gravellayer drilling and grouting method, a coal bed work face top plate can be effectively strengthened, a gravel water containing layer is transformed into a water resisting layer or a weak water containing layer, and threats to coal bed work face recovery due to hole gap water are eliminated.

Description

technical field [0001] The invention relates to the technical field of drilling and grouting construction of a water-rich gravel layer on the roof of a coal mining face, in particular to a drilling and grouting method for a water-rich gravel layer on the roof of a coal mining face. Background technique [0002] The bedrock of the coal seam roof in some mining areas of the North China type coalfield is relatively thin, consisting of sand, sandy gravel, sandy pebble, semi-consolidated glutenite and marl, overlying Quaternary and Neogene thick unconsolidated pore water. Because the bedrock (thickness: 4-40m, average 9m) of the wellfield is weathered to varying degrees, with developed fissures and poor water-repellent performance, the existence of the roof caving fissure zone after mining in the working face will completely lose the water-repellent effect. If reasonable and effective maintenance measures are not taken, not only the recovery efficiency will be reduced, the initia...

AI Technical Summary

Problems solved by technology

Scholars at home and abroad have little research on the grouting reinforcement of the aquifer on the roof of the working face. The current grouting reinforcement methods often fail to meet the expected requirements and progress goals during construction. Generally, the drilling holes are shallow and densely packed. Only 1-2m, the construction process is complex and cumbersome

As for the grouting of the water-rich gravel layer on the roof of the coal mining face to strengthen the water-proof and maintain the integrity of the roof, there is no mature technology in China at present.

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