The effect of standing support stiffness on primary and secondary bolting systems.
Tadolini SC; Barczak TM; Zhang Y
Proceedings of the 22nd International Conference on Ground Control in Mining, August 5-7, 2003, Morgantown, West Virginia. Peng SS, Mark C, Khair AW, Heasley KA, eds., Morgantown, WV: West Virginia University, 2003 Aug; :300-307
Standing crib supports have been applied in underground mining programs to resist large roof movements and sustain high loads. The strength and deformation capability of these systems has been documented under both lab and field conditions. The parameter that has not been examined and is not well understood is the effect that a crib or other types of standing support has on the primary and secondary bolting systems. A crib support system with low system stiffness may allow large amounts of closure and deformation and cause the bolting systems to yield or even fail. Conversely, cribs or standing support that are too stiff may experience brittle or buckling failures, negating the advantage of the intrinsic supports previously installed. Using a combination of field measurements and three-dimensional finite-element modeling techniques, the relationship between system stiffness and the subsequent performance of the installed bolting system is evaluated. Additionally, a simple method for calculating the combined system stiffness for standing supports when using materials with different strengths such as steel, concrete, wood, etc., is presented.
Ground-control; Underground-mining; Coal-mining; Longwall-mining; Mine-roof-supports; Numerical-modeling; Control-technology; Engineering-controls
NIOSH, Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
Peng SS; Mark C; Khair AW; Heasley KA
Proceedings of the 22nd International Conference on Ground Control in Mining, August 5-7, 2003, Morgantown, West Virginia