Roof wedge stability: a simple analytical model and numerical validation using deformable blocks.
NARMS-TAC 2002, "Mining and Tunnelling Innovation and Opportunity," Proceedings of the 5th American Rock Mechanics Symposium and the 17th Tunnelling Association of Canada Conference, July 7-10, 2002, Toronto, Ontario, Canada. Hammah R, Bawden W, Curran J, Telesnicki M, eds., Toronto, Ontario, Canada: University of Toronto Press, 2002 Jul; 1:663-669
Wedge-shaped roof falls are an extremely common mode of failure of underground openings in jointed rock. Although a number of sophisticated analytical solutions have been developed to determine the stability of roof wedges, a simple approach may also be used to provide an estimate of wedge stability. The simple two-dimensional model assumes the wedge is symmetric in shape and the resultant force on the sides of the wedge is horizontal. It may be used to determine stability of a wedge given dip angles of the joints forming the sides of the wedge and the friction angle, assumed to be the same on both surfaces. It may also be used to calculate the friction angle for stability given the dip angles of the joint sets. Numerical analyses previously conducted using the distinct element Inethod (Itasca's UDEC software) show excellent agreement with the simple analytical solution, for one specific set of conditions and a limited sensitivity analysis with rigid blocks. The results of a more in-depth sensitivity analysis with deformable blocks, presented here, show that the numerical results are quite insensitive to substantial variations in the Young's modulus and Poisson's ratio of the rock, orientation and stiffness of the joints, and ill situ stresses.
Mining-industry; Underground-mining; Mine-shafts; Models; Longwall-mining; Room-and-pillar-mining; Coal-mining; Coal-processing; Ground-stability; Ground-control; Analytical-models; Analytical-processes; Analytical-chemistry; Computer-software; Computer-models
Hammah-R; Bawden-W; Curran-J; Telesnicki-M
NARMS-TAC 2002, "Mining and Tunnelling Innovation and Opportunity," Proceedings of the 5th American Rock Mechanics Symposium and the 17th Tunnelling Association of Canada Conference, July 7-10, 2002, Toronto, Ontario, Canada