Grouting reconstruction of loose aquifer overlying work face and its effect test

In order to liberate the shallow quaternary loose aquifer coal pillar resources, taking the 1010-1 working face of the first mining area of Wugou Coal Mine as the test object, the grouting reinforcement test of quaternary loose aquifer and the weathering zone of the bedrock at the bottom was carried out by using the splitting grouting method and the grouting technology combining continuous and intermittent grouting. The results show that: the quaternary loose aquifer control area has complex lithology and weak water content, and mainly receives runoff recharge from the lateral area. The grouting reconstruction project adopts the water displacement and sand fixation scheme of the ground straight hole combined with the directional oblique hole row by row; the strength of the mixed slurry is subject to the ratio of fly ash, and the strength and stone rate of the mixed slurry are higher than those of the cement net slurry. When the fly ash content is 20%, the stone rate is the highest; the diffusion of grout in the quaternary loose aquifer is very uneven, the grouting process needs to control the grout diffusion range by controlling the grouting amount, the influence of grouting on the surface is reflected in the grout diffusion and pressure conduction, and the pressure conduction is the main one; after injection, the true density and water content of the core hole samples slightly increased, while the compressive strength, tensile strength and shear strength slightly increased; with the increase of sampling depth, the compressive strength of the rock layer in the wind-oxidized zone of bedrock increased first, then decreased and then increased, and the compressive strength increased about 2-5 times.