A method for head-on prevention of top-coal leakage in coal roadway tunneling in extremely soft and thick coal seams in sliding structural areas

Abstract

The invention discloses a top coal leakage and puking preventing method for tunneling and heading in an extremely soft thick coal seam coal roadway of a sliding tectonic zone. The method comprises thefollowing steps that when the roadway is tunneled, tunneling and anchor net supporting are conducted in sequence according to the circular step distance in the axial direction of the roadway; firstly, after half of a anchor rod spacing part is tunneled in front of an anchor net supported section, a plurality of structural compensating anchor rod holes are drilled in half spacing of the beforehand-anchor-net-supported section of a top plate of the roadway, and prestressed structural compensating anchor rods are installed in the structural compensating anchor rod holes; the other half of the anchor rod spacing part is continued to be tunneled; anchor net supporting of normal construction is conducted at the top of the roadway according to a pre-designed anchor net supporting plan, and prestressed anchorage is realized; and the next cycle of construction is conducted until the roadway tunneling and anchor net supporting are completed. By means of the top coal leakage and puking preventing method, the top coal leakage and puking of for tunneling and heading in the extremely soft thick coal seam coal roadway of the sliding tectonic zone and loosening and creepage of the back portion top coal of tunneling and heading can be effectively prevented, and the safety of construction is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of coal mine mining, and in particular relates to a method for head-on prevention of top coal leakage in tunneling of extremely soft and thick coal seam coal roadways in sliding structural areas. Background technique [0002] After the coal-forming strata in the Zhengzhou mining area were affected by the strong sliding structure, the original structure and structure of the coal have been severely damaged. The hardness coefficient of the coal seam is generally below 0.1-0.3, and the thickness of the coal seam changes sharply between 0-37.8m, which is a typical Powder flake tectonic coal. Due to the low strength of the coal seam, easy loosening and rheology, the top coal is easy to leak during the roadway excavation, and the implementation of anchor net support is extremely difficult. The problem of easy leakage of coal when driving head-on has become a major problem in whether the bolt-mesh support technolog...

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Problems solved by technology

[0003] At present, based on the modern bolt support concept of high strength, high stiffness, high reliability and low density, the high prestressed strong bolt support technology has been widely used in various coal mine roadways, but for the coal body in the sliding structure area, the Due to the loose and easy rheological conditions, there are few studies on how to effectively avoid the leakage of the tunneling head and the weakening of the top coal behind the tunneling head. Successfully implemented, this type of coal roadway has always been a forbidden area for high-strength prestressed anchor mesh support

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