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Comparison of models to evaluate in situ shield loading.
Barczak TM; Schwemmer DE
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9327, 1990 Jan; :1-75
The U.S. Bureau of Mines is conducting research to optimize the utilization and design of mine roof support systems. This report describes methods to evaluate resultant loading on longwall shields, defined as external resultant vertical and horizontal force acting on the canopy and base. Four models are considered: two rigid-body models, an elastic model, and a numerical model. The rigid-body models equate measured internal shield forces to unknown external resultant shield forces (loads) through rigid-body analysis of static equilibrium requirements. The elastic model develops a solution to shield mechanics by evaluation of the load-displacement relationship and stiffness characteristics of the support structure. The numerical model is a two-dimensional finite-element representation of a shield structure. Model determination of resultant shield loading is compared to controlled loading of a shield in the Bureau's mine roof simulator. Parameters investigated are shield height, canopy contact configuration, canopy and base horizontal constrainment, and boundary conditions imposed by vertical and horizontal shield displacements. It is concluded that rigid-body models are most applicable to in situ measurement of shield loading. Applications requirements and potential error sources are discussed.
IH; Report of Investigations
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9327
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division