Gob-side entry narrow coal pillar advanced grouting reinforcement method

Abstract

The invention provides a gob-side entry narrow coal pillar advanced grouting reinforcement method. The method comprises the steps that before extraction of a gob-side entry upper section working face,a row of drill holes are formed in one side of an excavated upper section entry in the extending direction of a coal pillar; the drill holes are detected through a drill hole penetrometer; accordingto obtained information data of pressure and displacement in the drill holes, the compression degrees of the coal pillar at different depths and the development condition of cracks in a coal body areanalyzed, grouting reinforcement operation can be directly conducted on the part, with the large crack development, in the coal pillar, and fracturing operation is conducted on the part, with the small crack development, in the coal pillar; fracturing operation is conducted on the part, with the small crack development, in the coal pillar through an electric pulse device; the impact wave fracturing range is observed till fracturing of all the areas, with the small coal pillar cracks, in the whole upper section entry is finished; and on the basis of original anchor net supporting of the coal pillar, grouting anchor rods are placed in the drill holes to conduct grouting reinforcement on the interior of the coal pillar. According to the method, advanced reinforcement operation of the coal pillar can be effectively achieved.

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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