The weakly cemented soft rock strata in the western mining area are extremely unstable, and the roadway is often arranged in the coal seam, thus forming two kinds of roadway layout ways-the whole coal roadway and the half-coal and semi-rock roadway. Based on contact element method and nonlinear contact theory, the numerical models for two types of roadway layout in weakly cemented soft rock are established. The separation deformation mechanism of the roof is analyzed by considering the interface effect of rock strata, and the deformation laws of the roof, two sides and the floor are revealed. Furthermore, the evolution characteristics of two types of roadways under different roof stiffness are obtained, and their catastrophic development processes are clarified. The results have shown that, the deformation of the roof, floor and two sides of the two types of roadway is non-synergistic. The displacement of the floor is fast and relatively small. The deformation of the surrounding rock is dominated by the roof and the two sides. In comparison, the stability of the whole-coal model is better. When the roof stiffness varies, the vertical displacement of the monitoring point is characterized by the "step jump" initially and then steadily increases to a stable value. Moreover, the closer to the roadway, the larger the vertical displacement of the monitoring point, the more obviously the displacement jumps The displacement "step jump" can be regarded as a sign of unstable damage to the surrounding rock. On-site borehole television detection of the separation layer shows that the numerical calculation results are of high reliability. © 2019, Editorial Board of Journal of Mining & Safety Engineering. All right reserved.
