Design Optimization In Underground Coal Systems The Roof Truss An Analysis With Applications To Mine Design

Author : J. Richard Lucas
Publisher :
ISBN 13 :
Total Pages : 59 pages
Book Rating : 4.:/5 (942 download)

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Download or read book Design Optimization in Underground Coal Systems written by J. Richard Lucas and published by . This book was released on 1979 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research effort is to construct a Strata Simulator that will represent the strata behavior over the seam and face area. Included in the simulator will be the effects of the longwall support. The purpose of the simulator is to systematically vary the mining and support parameters, such as rate of mining, support resistances, and profiles to achieve optimum strata control. Simulator input will comprise the physical description of the seam and surrounding strata, the geometry of the proposed layout, and the limits and characteristics of the support. Empirical relationships will be drawn from underground measurements of such data as roof deflection, support loads, and mining rates for each of the mines studies. Such approaches as the finite-element analysis will be used to modify the empirical equations developed to produce generalized relationships for the computer simulator. An alternative to conventional pillar design in room and pillar mining is the yield-pillar concept which makes it possible to raise the extraction ratio in room-and-pillar mines at great depths. At present, field data concerning yield pillars are scarce, and therefore, empirically-based design models cannot be used with confidence. Part of this research effort offers a theoretical method of yield-pillar design based on a non-linear, three-dimensioned, finite-element analysis to determine the stability of mine-panel pillars. A modification of the obliquely-installed roof bolts, the roof-truss, utilizes the concept of post-stressing so that a beneficial support effect is imposed, and it becomes very effective in preventing roof falls which could not be controlled by other means.It has not been used extensively, however, again due to the lack of design criteria and to drilling-equipment difficulties. Widespread use of the roof-truss will require that design criteria be developed.