Three-dimensional simulating method for goaf fracture ring morphology

Abstract

The invention discloses a three-dimensional simulating method for goaf fracture ring morphology. The method comprises the steps that according to the space similarity ratio between a coal seam and overlaying rock and time similarity ratio of coal seam working face propelling, a three-dimensional similar simulation test body is manufactured; according to the site mining working face ground stress situation and the mining sequence, the dynamic process of coal mine working face propelling under the three-dimensional stress condition is simulated; an embedded stress sensor is utilized for monitoring stress changes of a top plate and a bottom plate of a goaf in the mining working face propelling process, and a dynamic resistance strain gauge is utilized for recording data; after mining working face propelling simulation is finished, a tracer agent labeling method is used for carrying out drilling to pry and observe the goaf fracture morphology of the simulation test body, the top plate and the bottom plate of the goaf are separated layer by layer and section by section, and statistics is carried out on fracture data of all layers and all sections; according to the statistical fracture data, three-dimensional software is utilized for drawing a goaf fracture ring morphology simulation image. The method has the advantages that a three-dimensional mode is adopted for simulating the goaf fracture development morphology, and therefore the position of extraction holes can be determined conveniently and accurately.

Description

technical field [0001] The invention belongs to the field of gas drainage, in particular to a three-dimensional simulation method for the shape of a fissure circle in a goaf. Background technique [0002] The source of gas in mine excavation space is mainly the gas gushing out of the working face and goaf and the gas gushing in from adjacent layers. The amount accounts for more than 30-40% of the total gas emission at the working face, and the most is as high as 70-80%. The large amount of gas emission in the goaf often leads to the frequent gas exceeding the limit at the working face, so the production is forced to stop. [0003] Our country attaches great importance to the study of gas migration laws in goafs, and has gained rich experience in gas drainage technology and drainage techniques in goafs, but there are still some problems, such as the general effect of gas drainage in goafs. Poor, low extraction rate and other issues. The reasons are analyzed because the layo...

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Problems solved by technology

Therefore, the traditional gas drainage drilling method is difficult to correctly determine the drilling location

[0005] Some scholars use two-dimensional similar simulation, numerical simulation and other methods to determine the distribution of cracks in the goaf. Since the two-dimensional similar simulation cannot accurately reflect the change of stope stress, and the numerical simulation lacks experimental verification, these methods cannot be accurate. Reflects the distribution of fractures in the goaf, so there is limited guidance for determining the location of the borehole in the goaf

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