Determination method for hole sealing parameters of extraction drilling grouting and corresponding hole sealing method

Abstract

The invention provides a method for determining grouting hole sealing parameters of an extraction drill hole and a corresponding hole sealing method. The method comprises the steps that S101, the drill hole radius r0 of the gas extraction drill hole, the length L of a grouting hole sealing section and the radius rc of an extraction pipe are measured; the original ground stress sigma0 of the coal body around the drill hole; the original gas pressure of the coal seam is P0; the cohesive force of the coal body is c, and the porosity psi of the friction angle hole wall coal body in the coal body; s103, on the basis of a Finner correction formula and the parameters measured in the step S101, the radius RP of the plastic zone of the drill hole is obtained through calculation; s104, according to the parameters measured in the step S101, including the drilling radius r0, the length L of a grouting hole sealing section, the radius rc of an extraction pipe, the cohesion c of a coal body, the original ground stress sigma0 of the coal body, the porosity psi of a friction angle hole wall coal body in the coal body and the drilling plastic zone radius RP obtained in the step S103, the total grouting amount Q for drilling hole sealing is determined; the determined total grouting amount Q is used for conducting extraction drilling grouting hole sealing, and the hole sealing quality and the gas extraction effect can be improved.

Description

technical field [0001] The invention relates to the technical field of mining construction, in particular to a method for determining parameters of drainage drilling grouting and sealing holes and a method for drainage drilling grouting sealing. Background technique [0002] Gas drainage is the main way of gas control in the mining process, which is of great significance to mining safety, environmental protection and resource utilization. Improving the concentration of gas drainage is an important problem that needs to be solved in domestic mines. Drilling and sealing technology is an important part of mine gas drainage engineering, and it is also an important factor affecting the concentration of gas drainage. [0003] After the borehole is excavated, the equilibrium state of the stress field around the borehole is broken, the original rock stress field is redistributed, and the coal and rock mass around the borehole produces stress concentration. Under the action of the r...

AI Technical Summary

Problems solved by technology

[0011] For example, the calculation of the amount of grouting is only enough to fill the space in the borehole, but after the grout is injected, it will leak into the coal around the hole wall, resulting in insufficient amount of grout remaining inside the borehole. It is easy to form a crescent-shaped crack at the top of the borehole, thereby forming a channel for air leakage in the hole; and it is difficult for the slurry infiltrated into the coal wall to completely achieve the plugging of the borehole without the "compression" of sufficient grouting pressure depth, so the air leakage channel outside the hole has not been completely blocked

If the grouting pressure is not high enough, the grouting time will be prolonged. Once the setting time of the grout is exceeded, the grout cannot meet the required sealing requirements.

Therefore, it is difficult to ensure the continuity and stability of the drilling drainage effect by the "two plugging and one injection" hole sealing method implemented by experience.

[0012] In order to improve the quality of hole sealing and the effect of gas drainage, there is an urgent need for a method to determine the sealing parameters of drainage drilling grouting, so as to overcome the difficulty of guaranteeing the effect of drilling drainage due to the "two plugging and one injection" sealing holes that are implemented empirically technical issues

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