Study on superposition relation of coal deformation under adsorption

In order to verify that the deformation of coal body is the superposition of coal matrix adsorption expansion (desorption shrinkage) deformation and effective stress deformation, based on the mechanism of adsorption swelling deformation, the verification method of superposition relationship of coal deformation under adsorption was proposed. The superposition relationship of coal deformation under adsorption is verified by using this method combined with experimental data. The results showed that the average relative error of theoretical value and experimental value proportion coefficient of isothermal adsorption experiment of anthracite, lean coal and 1/3 coking coal is 4.27%. The deformation of coal body, the adsorption expansion deformation of coal matrix and the deformation of coal body under the effective stress are in accordance with the superposition relationship. Through discussion, it is concluded that the verification method of superposition relation of coal deformation is suitable for reversible deformation and residual deformation of desorption curve, but not for rich deformation.