煤田地质与勘探2026，Vol.54Issue(5)：100-112,13.DOI:10.12363/issn.1001-1986.25.12.0888
深部开采诱发煤与瓦斯突出的煤体失稳机制
Mechanisms underlying coal instability during coal and gas outbursts induced by deep mining
摘要
Abstract
[Objective]The gradual depletion of shallow coal resources drives a shift to the mining of deep coal seams.However,the complex deep mining environment significantly increases the potential risks and severity of coal and gas outbursts.Therefore,there exists an urgent need to investigate the mechanisms underlying the mechanical instability of coals under deep mining,aiming to provide guidance for the safe mining of deep coal mines.[Methods]By integrating physical experiments,numerical simulations,and theoretical analysis,this study investigated coal and gas outbursts un-der burial depths of 500 m,1 000 m,and 1 600 m and established a multi-field coupling model that incorporates the coal deformation,gas flow,and coal damage fields.Furthermore,it revealed the mechanisms underlying the mechanical in-stability of coals during coal and gas outbursts under deep mining.[Results and Conclusions]Physical experiment res-ults indicate that during coal and gas outbursts,the coal seams exhibited a rise in the pressure relief rate as the burial depth increased,with the relative outburst intensity increasing to 29.05％,38.05％,and 42.70％under burial depths of 500 m,1 000 m,and 1 600 m,respectively.The post-outburst temperature of the coal seams was found to decrease signi-ficantly as the burial depth increased,with the maximum temperature drops reaching 0.17℃,0.37℃,and 0.55℃ un-der burial depths of 500 m,1 000 m,and 1 600 m,respectively.During coal and gas outbursts,the migration velocity of pulverized coals was observed to increase with the burial depth,reaching peaks of up to 22.08 m/s,22.87 m/s,and 26.58 m/s under burial depths of 500 m,1 000 m,and 1 600 m,respectively.Overall,a greater burial depth correspon-ded to a stronger outburst dynamic.Numerical simulation results reveal that with decreasing lateral pressure coefficient and increasing gas pressure during coal and gas outbursts,the coal damage zone evolved from a semicircular shape to a butterfly shape while propagating primarily in the vertical direction.The deflection angles of the damage cavity in-creased to 8.1°,19.0°,and 34.4° under burial depths of 500 m,1 000 m,and 1 600 m,respectively.Under the latter two burial depths,the maximum permeability occurred at the exposed surface of coals,reaching 10.8 times and 47.5 times the initial permeability,respectively.The maximum seepage force was also identified at the exposed surface,reaching up to 3.62 MPa/m,7.74 MPa/m,and 11.93 MPa/m under burial depths of 500 m,1 000 m,and 1 600 m,respectively.Based on the variation characteristics of vertical stress,permeability,and seepage force during the transition from moderately deep to ultra-deep mining,the coal seams can be divided into a rapid change zone,a fluctuation zone,and a stable zone.Under deep mining,the coals were subjected to high in-situ stress and high gas pressure,manifested as high vertical stress and high seepage force,respectively,which led to coal failure,an expanded plastic zone,and significantly elev-ated outburst risks.Further theoretical analysis of the mechanical properties of deep coals demonstrates that the coal and gas outbursts experienced four mechanical evolution stages:preparation,initiation,development,and termination.The analytical results systematically reveal that the mechanical instability of deep coals was jointly governed by high in-situ stress and high seepage force.This finding provides a new theoretical perspective for the mechanical evolution process of deep coal and gas outbursts.Given the damage characteristics of deep coals,along with the high seepage force in their fluctuation zones,it is necessary to implement intensified measures to enhance pressure relief and permeability in the prevention engineering of coal seam and gas outbursts at depth.These efforts will help break the coupling between the in-situ stress concentration and high gas pressure accumulation and reduce the energy that induces deep coal and gas out-bursts in fluctuation zones.关键词
煤与瓦斯突出/失稳机制/深部开采/煤体损伤/孔洞偏转角/渗透力Key words
coal and gas outburst/mechanism of coal instability/deep mining/coal damage/deflection angle of a dam-age cavity/seepage force分类
矿业与冶金引用本文复制引用
张超林,李运富,李忠辉,王恩元,杨世纪,陈佳伟,王梦..深部开采诱发煤与瓦斯突出的煤体失稳机制[J].煤田地质与勘探,2026,54(5):100-112,13.基金项目
国家自然科学基金项目(52274242,51904293) （52274242,51904293）
贵州省科技计划项目(黔科合支撑[2023]一般279) （黔科合支撑[2023]一般279）
江苏省科技计划专项资金项目(BM2022013) （BM2022013）
