Simulation of Sidewall Failure in Coal Mine Roadways Using an Extended Continuous Joint Model

Coal is well developed with beddings, and the beddings play an important role in the stability of tunnel stability of coal mine. This study focused on jointed rock mass with two sets of joint and proposed an extended ubiquitous model and associated numerical implementation accounting for joint spacing to represent geometric features of coal. The failure criteria of two sets of joint proposed in this paper not only accounted for joint spacing, but also contained the ubiquitous joint model. This extended theory was validated against the discontinuous deformation analysis method, the plane of weakness theory and experimental results for jointed coal with different joint fabric. The model is also used to analyze tunnel stability of roadways in coal mine with different joint spacing. The ubiquitous joint model could simulate jointed coal with small joint spacing, but for that with larger joint spacing, the ubiquitous joint model is not applicable and the joint model containing joint spacing proposed by this paper should be used. A series of comparisons demonstrated that the proposed model was capable of considering the influence of joint spacing on jointed coal tunnel with two sets of joint. © 2017, ASM International.