Authors: K.H. Lee, V.G. Kazantsev, O.V.1,2 Tailakov, H.U. Lee, A.I. Fomin

Title of the article: Coal formation damage accumulation model at coal mine degassing wells

Year: 2024, Issue: 1, Pages: 52-65

Branch of knowledge: 2.8.6. Geomechanics, destruction of rocks by explosion, mine aerogasdynamics and mining thermophysics

Index UDK: 622.453

DOI: 10.26730/1999-4125-2024-1-52-65

Abstract: Physical and mathematical model of damage accumulation and destruction of coal-bearing massif is presented, taking into account influence of rock pressure on development parameters of one or several destruction fronts in massif simultaneously. The generalized model of stability and strength of the mountain massif is based on a system of relations - a static version of the theory of strength, stability and an exponential dependence that associates long-term strength with the stresses acting in the massif in the interpretation of S.N. Zhurkov and S. A. Arrhenius. Remaining on the phenomenological representations of the mechanics of continuous media, the continuous accumulation of scattered damages is represented as defects of the type of microcracks, developing in a set per unit of rock volume. In the formulation of L.M. Kachanov, the kinetics of damage accumulation is presented in the form of a dependence of the rate of damage accumulation on the level of damage and the stresses acting in the array. The problem of accumulation of damage and destruction of rocks is based on finding the minimum functional of the potential energy of the coal-bearing massif, the sampling of which is carried out using the finite element method. The implementation of the damage accumulation model is represented by a comparative analysis of damage accumulation and coal destruction at vertical and horizontal degassing wells. Numerical examples show the positive and negative aspects of the mechanical operability of the well variants over time. It was found that all other things being equal (formation depth, physical and mechanical characteristics of the coal mass, well sizes) the rate of damage accumulation in a horizontal well is significantly higher than in a vertical well. It has been shown that rational selection of the coal seam degassing scheme by wells should include a mandatory procedure for studying the behavior of the coal mass near the well, taking into account the depth of the deposit, the structure of the mass, the crack formation index, the limits of long-term tensile strength and compression of coal, the expected time of well operation.

Key words: modeling coal seam well damage destruction stress state destruction front

Receiving date: 15.01.2024

Approval date: 15.02.2024

Publication date: 12.03.2024

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