Method for controlling high mine pressure of open-air roadway by hydraulic fracturing

Abstract

A method for controlling high mine pressure of an open-air roadway by hydraulic fracturing comprises the following steps of determining a hard rock stratum of a roof according to a geological information bar chart of a coal face; designing a control drilling hole; respectively controlling abutment supporting pressure and lateral supporting pressure; slotting or slitting in the bottom of the hole after hole drilling construction is finished so as to achieve the purpose of directional fracturing; applying a hydraulic fracturing process; and weakening the hard roof or cutting off the hard roof along a directional fracturing slot of the drilling hole so as to transfer stress or weaken surrounding rock and reduce the lateral supporting pressure and the abutment supporting pressure of the open-air roadway. A weakening zone in the surrounding rock can effectively absorb or weaken impact stress waves; a dynamic disaster of rock burst caused by the reason that the hard roof cracks suddenly is avoided; and large deformation of the open-air roadway is controlled. The method for controlling the high mine pressure of the open-air roadway by hydraulic fracturing is not only applicable to controlling the high mine pressure of the open-air roadway with the coal face with the hard roof, but also is applicable to controlling the high mine pressure of the roadway of which a work face is in tunnelling crossing with a work face of an adjacent roadway during mining. Moreover, the method is simple, effective, safe and reliable, and is low in cost.

Description

technical field [0001] The invention relates to a method for controlling strong mineral pressure, in particular to a method for controlling the strong mineral pressure of a roadway with a hard roof in a coal mining working face, and is also suitable for the confrontation between the mining of the working face and the tunneling of the adjacent working face. Control the appearance of strong mine pressure in other roadways. Background technique [0002] Many mining areas in my country (such as Datong mining area, Shuozhou mining area, Yulin Shendong mining area, etc.) have a hard roof with high strength, large thickness and good integrity on the coal seam. When mining a coal seam with a hard roof, strong mine pressure appears in the roadway (dynamic disasters such as rock burst, or serious deformation of the surrounding rock of the roadway, and some deformations reach 50%, the maintenance cost is too high or even lead to the roadway being scrapped). Reasons for the appearance...

AI Technical Summary

Problems solved by technology

The reasons for the strong mine pressure in the roadway: 1. Due to the hard roof, the width and area of ​​the suspended roof adjacent to the goaf of the roadway are large, the influence range of the lateral bearing pressure of the roadway is large, the degree of stress concentration is high, and the surrounding rock of the roadway is unstable due to static load. Stable, difficult to support, high maintenance cost or even difficult to maintain

2. The failure of the hard roof to collapse in time leads to a large breaking step and a large compressive strength of the roof, which leads to a large impact of dynamic load disturbance on the advanced support section of the empty roadway.

3. The superimposition of strong advanced bearing pressure and strong lateral bearing pressure leads to dynamic disasters such as rock burst in the roadway, serious deformation of surrounding rock, strong mining pressure, and longer supporting section

Strengthening support, drilling, excavating pressure relief grooves, etc. have limited stress transfer effect and high cost, and blasting caving has limited roof pre-cracking range or potential safety hazards caused by blasting (high gas mine and blasting dynamic disturbance) problems

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