Gas-containing coal body expansion deformation measurement method

Abstract

The invention discloses a gas-containing coal body expansion deformation measurement method comprising the following steps that (a) drilling is performed through a coal seam to reach a bottom plate and then stopped; (b) a gas-containing coal body expansion deformation measurement device is fed to the drilling bottom; (c) the drilling section of the interface of the coal seam and a top plate is sealed by a hole sealing wooden plug, the upper space of the hole sealing wooden plug is filled by polyurethane and the numerical value P0 of a digital display stress meter is recorded; and (d) the numerical value P1 of the digital display stress meter is recorded after pushing the lower working surface, and spring deformation deltax, i.e. the expansion deformation of a gas-containing coal body, is calculated and obtained according to the Hooke's law deltap / k=deltax, wherein deltap=P1-P0. Drilling instability and hole collapse and other liable factors are overcome so that the expansion deformation of the gas-containing coal body can be accurately measured. Besides, the Hooke's law can be ingeniously utilized, and the expansion deformation of the gas-containing coal body can be indirectly reflected by the change of the spring stress so that the principle of measurement is simple and convenient; meanwhile, the measurement device is simple in the whole structure, easy to operate and suitable for large-scale popularization.

Description

technical field [0001] The invention relates to a method for measuring expansion and deformation of a coal body, in particular to a method for measuring expansion and deformation of a gas-containing coal body, and belongs to the technical field of anti-gas outburst safety management in coal mines. Background technique [0002] The "Coal Mine Safety Regulations" clearly stipulates: "When mining coal seam groups in coal and gas outburst mines, the protective layer must be mined first. After mining the protective layer, the protected area in the protected layer shall be excavated as a non-outburst dangerous coal seam. In protected areas, measures must be taken to prevent prominent dangers." Mining protection layer is the most effective regional outburst prevention measure to prevent coal and gas outburst, and it has been widely used in outburst mines with coal seam group mining conditions. Its essence is: after the protective layer is mined, the surrounding rock will expand an...

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Problems solved by technology

[0004] It is not difficult to see that the above-mentioned patents can measure the expansion and deformation of the gas-containing coal body, but in actual operation, because the drilling holes penetrate more layers, they are greatly affected by mining, especially when the lithology of the top and floor of the gas-containing coal body is relatively high. It is soft, the drilling is unstable, the hole wall is easy to peel off or even collapses, resulting in large errors in test results, or even errors, which seriously threaten the mining safety of mines

However, when the detection signals based on ultrasonic waves and electromagnetic radiation are observed, the detection signals are subject to more interference, which is more suitable for the detection of areas within the pressure relief range. It is difficult to detect the deformation and expansion of gas-containing coal bodies, with low accuracy and poor overall stability of the system. , It consumes a lot of manpower and material resources, and the cost is high, so it is not easy to promote on a large scale

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