Dynamic load deep mining area coal pillar instability unloading-solidifying-yielding multilevel prevention method

Abstract

The invention discloses a dynamic load deep mining area coal pillar instability unloading-solidifying-yielding multilevel prevention method. The method includes the steps that an entry protection coalpillar instability implementation target section is determined at first, namely a coal pillar high static load area is determined; then the target section is evenly divided into two unloading-solidifying-yielding implementation areas; an unloading-solidifying-yielding multilevel prevention technology is implemented in a partitioning mode; after grouting materials are solidified, rubber particlesof the grouting materials in the first unloading-solidifying-yielding implementation area and the second unloading-solidifying-yielding implementation area are compressed along with the increasement of the stress of a mining area main entry protection coal pillar instead of entirely acting on a resin material coagulation block body, and accordingly the effects of pressure yielding and energy absorption are achieved; the grouting materials are filled into high-pressure water jet flow slit drill holes, slots and fractures; and meanwhile, the grouting materials make the adjacent slots be connected into a whole to achieve the strengthening effect, and the strength of the mining area main entry protection coal pillar is improved.

Description

technical field [0001] The invention relates to the technical field of coal pillar stability control for roadway protection in deep mines, in particular to a multi-stage "unloading-fixing-letting" method for preventing and controlling coal pillar instability in deep mining areas under dynamic load. Background technique [0002] At present, with the improvement of mining technology and the application of automation and intelligent equipment, coal production has increased significantly, the shallow coal resources have been mined, and the mining depth has gradually extended to the deep. Most of the mining area roadways (track roadways, transport roadways, and return air roadways) in deep mines are arranged in coal seams. In order to ensure the stability of the roadways, 30-40m coal pillars are usually left between the roadways . The coal pillar in the mining area is an important part of the underground coal pillar. It shoulders the important task of ensuring the stability of t...

AI Technical Summary

Problems solved by technology

The defects of this technology are also obvious. According to the theory of rock burst prevention and control, when large-diameter drilling pressure relief, hydraulic slotting, deep hole blasting and other technologies are used to prevent rock burst, the target area of ​​the operation is the high stress concentration area of ​​the coal seam , so that the stress peak areas on both sides of the roadway are transferred or destroyed to the deep part, but the invention does not destroy or transfer the stress peak areas on both sides of the roadway, but uses the stress peak areas on both sides of the roadway as the sealing area, (see specific step d for details: After completing the hydraulic slotting of bedding drilling, seal the bedding drilling, and the sealing length is greater than the depth of the original stress zone of the coal seam drilling), which will not achieve the purpose of preventing rock burst, and will easily lead to dynamics in the roadway disasters, resulting in roadway deformation and instability, which cannot guarantee the safe and efficient production of coal mines, so the patent idea cannot provide a reference for the prevention and control of coal pillar instability in deep mining areas

Images