煤体有效应力与膨胀应力之间关系的分析

Relation between effective stress and swelling stress of coal body

有效应力公式是研究岩体和流体相互作用的基础公式之一,为了更加真实的描述煤体的受力状态,采用理论分析和试验分析的方法,分析了这种由于煤吸附瓦斯发生膨胀在约束条件下所产生的膨胀应力与有效应力的关系,并得出了膨胀应力与有效应力之间的关系式。分析可知,煤吸附瓦斯将发生膨胀变形,吸附量越大,膨胀变形越大,当这种变形受阻时将会产生膨胀应力膨胀应力的存在,将使煤体应力增加,煤体强度降低,煤体更易破碎,将增加煤与瓦斯突出的危险性。

Effective stress formula is the foundation of the study on fluid-solid coupled flow. In order to more accurately describe the stress state of coal and on the basis of elasticity theory and test, the authors study the relation between effective stress and swelling stress of coal and found the expressions of effective stress and swelling stress. By test and analysis it can be concluded that adsorbed methane-coal can generate the swelling deformation, and as gas content increases in coal seams, the swelling deformation becomes bigger. When the swelling deformation is restricted, swelling stress can be produced. Because of the existence of swelling stress, coal stress increases and coal strength reduces, so as to increase the danger of coal and gas outburst.