Experimental study of deformation properties of outburst prone coal induced by gas adsorption and desorption

In order to investigate the unique mechanical behavior of swelling deformation and contraction deformation effect of outburstprone coal each induced by gas adsorption and desorptionthe selfdeveloped gas adsorptiondesorption testing apparatus of coal containing high pressure gas was used to perform the adsorption swelling deformation and desorption shrinkage deformation test under different gas pressures.The results show that the deformation cure of the outburstprone coal specimen under different gas pressures have the same evolution law on timenamely vacuum contraction deformationaeration compression deformationadsorption swelling deformationdischarging swelling deformationelastic spring back deformation after releasing the pressure and desorption shrinkage deformationIn the process of the adsorption swelling deformation and desorption shrinkage deformationthe strain change rate of coal specimen decreases with time until it reaches a stable valuethe deformation law will basically follow the Langmuir equationBoth of the swelling deformation and shrinkage deformation of coal specimen shows anisotropythe total trends of strains perpendicular to the bedding and parallel to the bedding are consistencefor the crack distributions are different in the coalthe deformation perpendicular to the bedding is greater than that parallel to beddingThe swelling deformation of coal specimen and gas pressure present a good fitting effect of the Langmuir equation and quadratic functionbesidesthe shrinkage deformation of coal specimen and initial gas pressure present a good power functions and quadratic Function relationshipthere is residual deformation after gas desorption of the coal sample.