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Method for hard roof advanced precracking control caving in coal mine stope

A hard roof and stope technology, which is applied in ground mining, earth drilling, underground mining, etc., can solve the problems of difficult charging, potential safety hazards, and few on-site applications, so as to achieve hard roof control, easy operation, scientifically controlled effects

Inactive Publication Date: 2018-10-12
TAIYUAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At the same time, the weakening effect of hydraulic fracturing on the roof is uncontrollable, and the weakening effect on the thick and hard roof is not particularly ideal
③The controlled roof caving method of injecting static breaking agent into deep holes in the coal wall of the working face to crack the roof is a new type of pre-cracking method for hard roofs. It is currently in the scientific research stage and rarely used on site
Specifically, the patent uses calculations to determine the periodic topping step distance, and adopts a technical solution for forced topping by blasting on the rear side of the tail beam of the bracket. However, it is difficult to drill holes and charge charges behind the tail beam of the bracket and there are potential safety hazards.

Method used

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  • Method for hard roof advanced precracking control caving in coal mine stope
  • Method for hard roof advanced precracking control caving in coal mine stope
  • Method for hard roof advanced precracking control caving in coal mine stope

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Embodiment 1

[0036] Taking Shanxi Coal Transportation and Marketing Group Yuxing Coal Industry Co., Ltd. as an example, the direct top of No. 15 coal seam is K 2 Limestone, K. 2 Limestone is 5.40-7.80m thick, with an average thickness of 6.78m. It is dense and hard, and the lower part is often sandwiched with thin mudstone. This layer is particularly stable in the well field, with an average unidirectional compressive strength of 98.5MPa and an average uniaxial tensile strength of 11.2MPa. Hard and difficult to take off the roof board. The length of the 15101 working face of this mine is 150m, and the mining height is 4.49m, and the cycle progress is 0.8m. The working face adopts four-column support shielding bracket, the bracket is designed with a rated working resistance of 5900kN / frame, and the top control distance of the bracket is 4.5m. Among them, the relationship between the drilling length and the working face length is shown in Table 1.

[0037]

[0038] A method for advance...

Embodiment 2

[0052] The length of the working face is 160m, the mining height is 4.0m, the cycle progress is 0.6m, and the others are the same as in the first embodiment.

Embodiment 3

[0054] The length of the working face is 180m, the mining height is 3.8m, the cycle progress is 0.8m, and the others are the same as in the first embodiment.

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Abstract

The invention discloses a method for hard roof advanced precracking control caving in a coal mine stope, and belongs to the technical field of coal mining, and particularly relates to a hard roof advanced precracking control caving method for determining parameters of borehole layout, such as, the pore opening positions, the depth of drilling holes, the angle of the drilling holes and numbers of the drilling holes of hard roof advanced precracking drilling in the coal mine stope and calculating the explosive payload of the drilling holes. According to the characteristics of hard roof fracture,five blast holes in a fan shape are formed to form a fixed angle; the middle portion and the end of the a working face which are most difficult to break of the hard roof can be effectively pre-cracked, so that the roof can collapse as required; based on the characteristics of blasting, the blasting sequence of the blast holes from the middle portion of a cutting hole to both ends can maximize thefree surface of the blasting and reduce the explosive payload, and the operation is convenient; and a calculation formula of the explosive payload of the hard roof of preceding loosening blasting indeep hole is given quantitatively to enable the control of hard roof to be more scientific, quantitative, accurate and simple.

Description

technical field [0001] The invention relates to the technical field of coal mine mining, and in particular to the determination of the parameters of the drilling layout method such as the opening position, drilling depth, drilling angle and quantity of the hard roof of the coal mine stope, and the drilling charge amount Calculated rigid roof control caving method. Background technique [0002] Occur directly on the coal seam or directly on the thinner roof with high strength, large thickness, strong integrity, and undeveloped joints and fissures. After the coal seam is mined, it can be exposed in a large area in the goaf. The roof that is not easy to sag naturally is a hard roof. Due to the characteristics of the rock structure, the working face of the hard roof has strong pressure appearance, large dynamic load coefficient, large initial and periodic pressure steps, and is not easy to collapse on its own during the process of advancing with the working face. The character...

Claims

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Application Information

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IPC IPC(8): E21C41/18
CPCE21C41/18
Inventor 张小强姜玉龙王开张东峰弓培林岳少飞
Owner TAIYUAN UNIV OF TECH
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