煤与瓦斯突出不仅与地应力、瓦斯压力、煤岩体强度有关，而且还和卸压区范围有关。卸压区越薄，集中应力区越接近工作面，卸压区煤体被冲破造成突出的可能性就越大。根据煤岩与其顶底板岩层接触类型不同，把煤岩体塑性区的求解分为柔弱端约束和固端约束两类，并运用不同的煤岩体破坏准则对这两种类型煤岩体卸压区宽度与塑性区宽度进行理论计算，得到相应的理论计算公式。煤矿企业可以根据实际情况，理论计算煤岩体塑性区宽度，从而确定安全宽度，以预防煤与瓦斯突出事故的发生。%Coal and gas outburst is not only related to the strata stress, the gas pressure and the strength of coal-rock mass, but also to the range of pressure relief area. The smaller the pressure relief area, the closer the stress concentration area to coal face, and the greater the possibility of outburst caused by coal’ s being broken in the stress relief area. In this paper, the solution of the plastic zone of coal-rock mass was classified as the weak-end constraints and the fixed-end constraint according to the different contact types of coal with its roof and floor strata, theoretical calculation was carried out on the width of the pressure relief zone and the plastic zone of the two types of coal-rock mass by using the failure criteria of different coal-rock masses, and corresponding theoretical calculation equation was obtained. The coal enterprises can theoretically calculate the width of the plastic zone so as to determine its safe width and prevent the occurrence of coal and gas outburst.
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