A coal mine roadway excavation and support method

Abstract

The invention discloses a coal mine underground roadway excavation and support method, which is mainly aimed at solving the problems that the surrounding rock of the roof is soft and broken, and the formation of the roadway is difficult, which further affects the safety and speed of the excavation, and the like during excavation of the three-soft and thick coal seam mining face. The method of the present invention divides the excavation of the entire cut-out space into three stages: the first passage is formed by breaking the roof, the second passage is formed under the undercover, and the third passage is formed by expanding the side of the coal body to be mined. The present invention can well adapt to the roof The extremely soft and broken roof of the thick coal seam working face with large cross-section is weak and broken, which can effectively prevent the occurrence of roof fall accidents.

Description

technical field [0001] The invention relates to a coal mine roadway excavation and support method, which is suitable for excavation and support of large cross-section cutting holes in thick coal seam working faces with extremely soft and broken roofs. Background technique [0002] The degree of mechanization and the scope of application of coal mining in my country are gradually increasing, and the height and width of the cutout in the working face are increasing. Generally, the excavation method of tunnel expansion and secondary roadway formation is adopted. In the secondary expansion of the roadway, it is easy to cause the cutout and roof fall accidents. Especially in the cut eye of the thick coal seam working face with very soft and broken roof, roof fall accidents occur frequently. Therefore, it is of great economic and social significance to ensure the safety of excavation and the stability of the surrounding rock in thick coal seam working faces with extremely soft and ...

AI Technical Summary

Problems solved by technology

[0003] At present, the main method of tunneling in the excavation working face is the secondary tunneling method of tunnel expansion. eye, but the safety hazard of eye-cutting and roof fall has not been completely eliminated

One of the main reasons is that because the width of the cut hole is often large, the width becomes the main controlling factor for the stability of the surrounding rock of the cut hole. The current secondary tunneling method of expanding the side of the guide tunnel only delays the time for the formation of the large width, and does not consider eliminating the large width. The deflection and buckling effect of the width cut hole, after the formation of the second side expansion cut hole, causes the roof of the cut hole to be weak and broken coal and rock caving

Coal-rock mass grouting reinforcement is one of the effective means to solve the coal-rock mass on the roadway roof, but it has not been widely used due to the large amount of pre-grouting work, poor roof grouting effect, and high cost.

To sum up, the existing hole-cutting tunneling methods show the following problems: 1) the existing hole-cutting tunneling technology can not achieve the purpose of preventing the roof from falling of the weak and broken coal and rock mass; 2) the existing hole-cutting pre-grouting Large technical engineering volume, large safety hazards, poor roof grouting effect, and high cost; 3) During the second side expansion process, the roof support is difficult, serious safety hazards, and the excavation speed of the cut hole is slow; 4) The cut hole roof cannot be eliminated Due to deflection effect and large-span buckling effect, there is always a hidden danger of roof fall

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