Advance grouting reinforcement method for narrow coal pillars in gob-side roadway

Abstract

A advance grouting reinforcement method for narrow coal pillars in gob-side roadways. Before mining at the working face in the upper section of the gob-side roadway, a row of drilling drills are arranged along the extension direction of the coal pillars on one side of the roadway in the upper section of the upper section that has been excavated. Borehole; use the borehole penetrometer to detect the borehole; according to the obtained pressure and displacement information in the borehole, analyze the pressure degree of the coal pillar at different depths and the development of cracks in the coal body. For the coal pillar The part with larger cracks can be directly reinforced by grouting, and the part with smaller cracks in the coal pillar can be cracked; the electric pulse device can be used to crack the part of the coal pillar with smaller cracks; observe the shock wave cracking range, until all the coal pillar cracks in the entire upper section of the roadway are cracked; on the basis of the original anchor net support of the coal pillar, grouting anchor rods are placed in the borehole to grout the inside of the coal pillar reinforcement. This method can effectively realize the advance reinforcement of coal pillars.

Description

technical field [0001] The invention belongs to the technical field of surrounding rock control of gob-side roadways in coal mines, and in particular relates to an advanced grouting reinforcement method for narrow coal pillars in gob-side roadways. Background technique [0002] At present, my country's coal mining is mainly in the underground mining mode, and the instability of the roadway surrounding rock is one of the main problems in deep mine mining. During the underground mining process, the surrounding rock deformation and instability of the roadway due to the impact of mining and roof pressure have seriously affected the safe and efficient production of coal mines. In the gob-side roadway, the deformation and instability of the narrow coal pillar on one side of the mining face is a common problem. In order to effectively solve this problem, it is usually reinforced by grouting after the coal pillar is damaged. This method is lagging Grouting, often because the timing...

AI Technical Summary

Problems solved by technology

During the underground mining process, due to the impact of mining and roof pressure, the surrounding rock deformation and instability of the roadway have seriously affected the safe and efficient production of the coal mine.

In the gob-side roadway, the deformation and instability of the narrow coal pillar on one side of the mining face is a common problem. In order to effectively solve this problem, it is usually reinforced by grouting after the coal pillar is damaged. This method is lagging Grouting, often because the timing of grouting is too late, the overall fracture of the coal pillar has been serious, and even has completely lost its bearing capacity, so the effect of grouting at this time has not reached the expected reinforcement effect, so that the coal mine cannot be guaranteed. safety production work

The other method is mining grouting in advance, that is, before the mining of the upper section of the working face, the coal pillar has not been affected by mining at this time. Although it has not been damaged, it will be affected by mining during the mining of the working face. Therefore, the coal pillar needs to be strengthened by grouting, so as to ensure that the mining of the upper section of the working face is The coal pillar can play a high load-bearing role, and it can also ensure that the coal pillar will not be affected by mining when the working face in the lower section is mined, thus effectively ensuring the safe production of the mine. However, the coal pillar at this time The porosity is often small, and it is not easy to carry out grouting operations, resulting in the inability to form an effective bearing body for the coal pillar

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