The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration accumulation. Exploring evolution law under condition drilling slitting construction has important theoretical significance guiding efficient drainage. generation process fissures also development accumulation its damage. Therefore, based on damage mechanics finite element theory, mathematical model established. variable defined by effective strain, elastoplastic constitutive equation established secondary program completed FORTRAN language. Using this program, numerical simulation 15-14120 mining face Pingdingshan No. 8 Mine carried out, effects different single borehole diameters, kerf widths heights distribution area surrounding degree are studied quantitatively. These provide a basis reasonable determination arrangement parameters at engineering site.