The roof caving and tunnel protecting method

Abstract

The invention relates to a method for controlling caving and lane-guarding. The method is characterized in that in a working surface roadway, drilling, blasting or cracking are carried out on a roof of a coal seam of complete hard strata with large thickness of a hanging arch in a goaf; bursting or cutting off are carried out on a complete hard roof strata with large thickness to facilitate the hanging arch in the goaf to collapse at the back of a force piece; collapsed waste rock fills the goaf, supports superincumbent stratum in a fissure zone and releases high bearing stress passed into the coal body adjacent to the goaf from weight of the large-thickness complete hard strata of the hanging arch in the goaf and the superincumbent stratum in the fissure zone thereof, so that the bearing stress in the coal body adjacent to the goaf is reduced and laneways in the space are protected. The method of the invention fundamentally improves stability of surrounding rock of laneways adjacent to the goaf and increases coal mining rate of ends of thick coal seam caving coal working surface.

Description

Technical field [0001] The invention relates to the technical field of the stability of the surrounding rock of a coal mine roadway. Background technique [0002] When there is a large and complete hard rock layer in the roof of the mined coal seam at a certain height, the hard rock layer will not rise to the goaf after mining, causing high supporting stress in the coal near the goaf. The supporting stress greatly affects the stability of the roadway in the coal near the goaf. For example, the 15# coal seam in a certain coal field and the 3# coal seam in a certain coal field contain complete and hard limestone or sandstone with a thickness of more than ten meters or even tens of meters in a certain range. The roadways near the mined-out areas, especially the mining roadways reserved for adjacent working faces by isolating the coal pillars, will produce large deformations and damages, and even fall, which seriously affects the normal use of these roadways. Through observation and ...

AI Technical Summary

Problems solved by technology

Therefore, increasing the support strength has a very limited control effect on the stability of the roadway surrounding rock near the goaf

[0011] 3) Repair the damaged roadway and reinforce the surrounding rock with grouting (cement slurry or chemical slurry), which not only greatly increases the amount of roadway repair work and material consumption, but also seriously affects the succession of the working face and production. Work properly

[0012] 4) The method of drilling pressure relief or blasting pressure relief on the two sides of the roadway or the floor to release the stress of the surrounding rock of the roadway will seriously damage the integrity of the surrounding rock of the roadway and increase the deformation of the roadway

However, within a certain range of the coal seam roof there is a large thickness of intact hard rock strata, and under the condition of long-term action of high bearing stress caused by the formation of a suspended roof at the edge of the gob, the reinforced support cannot be used for a long time, which will limit the passage and transportation of the roadway function, and the long-term control effect of strengthened support on the deformation and destruction of the surrounding rock of high bearing stress roadway is also very limited

[0014] To sum up, the current existing technology is still unable to effectively control the stability of the roadway near the goaf with hard rock formations on the roof of the coal seam. The fundamental method to improve the stability of roadway surrounding rock caused by high bearing stress

Images