Finite element analysis of three-way roadway junctions in longwall mining

Abstract This paper presents a three-dimensional finite element analysis of three-way roadway intersections in longwall mining, and assesses the stable/unstable behaviour of three-way intersections under a range of loading conditions. Loads were applied to the model by means of uniform stresses on the internal free faces. This method of loading the model from the inside helped to reduce its size and to eliminate the boundary effects. Stress concentrations and displacement results on the mid-height of the pillars, roof and floor strata adjacent to the three-way intersections and cut-throughs were calculated. Based on this study, guidelines for designing the support system for three-way intersections are suggested. The results were validated by a case study of a three-way intersection in an underground coal mine in the southern coal fields of the Sydney Basin.