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为揭示煤与瓦斯突出灾害机理,综合考虑地应力和瓦斯压力对煤体力学特性的影响,采用有效应力进行分析。在不同围压、不同瓦斯压力条件下进行煤体受载破裂试验,综合分析围压、瓦斯压力和有效应力对煤体力学特性影响。结果表明:围压载荷使煤体抵抗变形能力变强,瓦斯压力载荷使煤体抵抗变形能力变弱;有效应力相同时,煤体压密效果相同,只受到围压作用的煤体单轴抗压强度高、弹性模量低,达到峰值应力后抵抗变形能力强;同时受到围压载荷和瓦斯压力载荷,且有效应力相同时,煤体压密阶段和弹性变形阶段具有相同的压密效果、弹性模量和单轴抗压强度。对井下煤体进行有效应力分析,可以简化力学模型,为分析井下煤岩力学状态提供方法。
In order to reveal the disastrous mechanism of coal and gas outburst, considering the effect of geostress and gas pressure on the mechanical properties of coal, the effective stress was analyzed. Under different confining pressure and different gas pressure conditions, the test of coal load and rupture was carried out. The influence of confining pressure, gas pressure and effective stress on the mechanical properties of coal was analyzed comprehensively. The results show that the confining pressure can make the coal deformation resistance stronger and the gas pressure load weaken the deformation resistance of the coal. When the effective stress is the same, the compaction effect of the coal is the same and only by the confining pressure High compressive strength, low modulus of elasticity, strong resistance to deformation after reaching the peak stress, simultaneous confining pressure and gas pressure loading, and the same effective stress at the same compressive effect during the compressive and elastic deformation stages of coal, Elastic modulus and uniaxial compressive strength. The effective stress analysis of underground coal body can simplify the mechanical model and provide a method for analyzing the mechanical state of underground coal and rock.