受载突出煤体在内外应力作用下发生破坏从而诱发煤与瓦斯突出（简称“突出”），为进一步明确该过程中煤体破坏模式及力学作用机理，本研究基于大型突出物理模拟试验结果，分析了突出过程中的煤体力学状态、破坏模式及倾向性，研究结果表明：突出初期，高瓦斯压力梯度和应力共同作用下低强度煤体发生破坏，瓦斯压力和应力同时跌落；突出中期，煤体将再次表现出一定承载能力，应力和瓦斯压力将因此升高，而当其达到煤体的极限承载能力时，煤体会被再次破坏，应力和瓦斯压力将再次下降；突出后期，煤体的内外荷载无法达到其破坏强度，导致其所承受的应力荷载会产生大幅回升，瓦斯压力下降速率减缓。突出过程中瓦斯对煤体施加的作用力可等效为张拉作用，温度变化则可等效为对煤体的压缩作用。突出过程中有效应力集中区会反复地向煤体深部转移，并在突出终止时逐渐恢复至原始位置，有效应力值表现为间歇式的减小和增大过程。随着突出的持续发展，卸压区和集中区的突出煤体应力圆心位置将周期性的向τ-σ图的原点处靠近，但每个周期移动的距离逐渐缩短。此外，卸压区煤体在突出过程中最大主应力方向发生改变，且突出后期主应力差基本表现为持续增大的过程，而集中区的主应力差总体表现为先减小后增大的过程。突出煤体在压缩和张拉状态的动态演变过程中，表现出间歇性的趋于破坏和稳定状态，卸压区和集中区突出煤体在经历一个趋于破坏的力学状态后，将会随即进入另一个趋于稳定的状态。

The loaded outburst coal body is destroyed under the action of internal and external stresses,which in⁃duces coal and gas outburst(abbreviated as “outburst”). In order to further understand the coal body failure modeand mechanical action mechanism in the process,the coal body mechanical state,failure mode and tendency during theoutburst process were analyzed based on the results of large⁃scale outburst physical simulation test. The researchresults show that in the early stage of outburst,the low⁃strength coal body is destroyed under the combined actionof high gas pressure gradient and stress,causing gas pressure and stress to fall at the same time. In the middle stage ofoutburst,the coal body will once again show a certain bearing capacity, which will increase the stress and gaspressure. When the ultimate bearing capacity of coal body is reached,the coal body will be destroyed again,cau⁃sing the stress and gas pressure to continue to decrease. In the later stage of outburst,the internal and external loads of the coal body cannot reach its destructive strength,resulting in a sharp rise in the stress and a slower rate of gaspressure decrease. The stress exerted by the gas on the coal body during the outburst process can beequivalent to the tensioning action,and the temperature change can be equivalent to the compression action on the coalbody. During the outburst process,the effective stress concentration zone will repeatedly transfer to the deep partof coal body,and gradually return to the original position when the outburst is terminated. The effective stress valueshows an intermittent decrease and increase process. With the continuous development of outburst,the central positionof the stress circle of the outburst coal body in the stress relief zone and the abutment stress zone will periodically ap⁃proach the origin of the diagram of,but the distance moved in each cycle will gradually decrease. In addition,the max⁃imum principal stress direction of the coal body in the stress relief zone will change during the outburst process,and the principal stress difference in the later stage of outburst basically shows a continuous increase process.However,the principal stress difference in the abutment stress zone generally shows a process of first decreasingand then increasing. During the dynamic evolution process of compression and tension state,the outburst coal bodyshows an intermittent tendency to be destroyed and stable. The outburst coal in the stress relief zone and the abutmentstress zone will enter another stable state immediately after experiencing a mechanical state that tends to fail.