Effect of initial load level of axial unloading on mechanical properties of coal contained gas
Abstract：Taking briquette samples made of fat coal as the object of study, mechanical properties under triaxial com- pression and axial unloading of different initial load level in the conditions of certain confining pressure and gas pres- sure were studied. The results show that the deformation features and deformation phase distribution is very similar with characteristics of raw coal under triaxial compression, especially in compression compacting step and linear elasticity step;nonlinear characteristics are showed in the process axial unloading;nonlinear characteristics are increased as the increasing of initial load level. The average elastic modulus is gradually smaller in process of axial unloading, the effect caused by gas pressure on deformation of coal contained gas is gradually bigger;the relation between axial stress and axial strain of coal contained gas is expressed by exponential equation in process of axial unloading.
Keywords：axial unloadingcoal contained gasmechanical properties
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 259-263 )