Horizontal stress related failure in bedded mine roofs-insightfrom field observations and numerical models

摘要

As part of a project to develop improved roof support strategies, numerical model analyses were conducted to better understand horizontal stress related failure of bedded roof rocks. Detailed numerical models were used to simulate the bedded roof rocks, failure initiation in individual beds, and the progression of failure under increasing horizontal stress. The studies showed that classical beam theory is useful for understanding the general response and potential failure of bedded rock. The initial curvature of the rock laminations and the relatively stiff end-loading conditions in a mine roof appear to limit the potential for sudden catastrophic buckling of roof beds in the situations modeled. "Cutter" type roof failure near the excavation corners was more likely to occur in the models when the lamination interfaces were weaker and less stiff. A ground response curve developed from numerical model results indicated that support pressures would have to be impractically high to prevent horizontal stress related failure of the roof rocks from taking place in a laminated roof