Evolution law of stress-deformation-permeability of coal pillar along gob and its effect on stability of coal pillar

Abstract

The interaction between stress field and seepage field is mainly manifested in two aspects: on the one hand, the change of stress field causes the change of structural plane such as joints and fractures in rock mass, and then changes the permeability of rock mass; On the other hand, the seepage force of seepage field will change the original stress state in rock mass. The two aspects of stress field and permeation field influence and interact with each other all the time, reaching a dynamic stable state, and this dynamic relationship forms the fluid-solid coupling mathematical model. Permeability coefficient is a bridge of interaction and coupling between stress field and seepage field. Only by establishing the relationship between permeability coefficient and stress field or strain field, can the influence of stress field on seepage field be reflected and the real fluid-solid coupling analysis be realized. As a governing equation as important as the constitutive equation in the coupled numerical analysis of stress field and seepage field, permeability coefficient-volumetric strain can be used in numerical analysis to make the calculated results more consistent with engineering practice.