Shield mechanics and resultant load-vector studies. Report of Investigations/1986
The term resultant load vector is defined as the representation of the forces applied to a longwall roof-support element by strata activity through a single, quantifiable measure of support resistance. The relatively complex kinematics of the shield structure prohibit determination of support resistance simply from the summation of leg forces. In the research reported in the Bureau of Mines study, the mechanics of the shield structure were evaluated and a technique was developed whereby the resultant shield loading could be determined by instrumenting supports with pressure transducers and strain gages to measure leg, canopy capsule, and lemniscate link forces. The technique was laboratory tested in the Bureau's Mine Roof Simulator. Functional relationships among variables were assessed, and confidence intervals were established for prediction of the resultant load-vector parameters. Resultant load measurements were taken on five instrumented shields on an active longwall face in Colorado. Results were analyzed and found to be consistent with shield mechanics and anticipated roof behavior. Benefits to be derived from the research, future efforts, and long-range goals are discussed.
- Research Organization:
- Bureau of Mines, Pittsburgh, PA (USA). Pittsburgh Research Center
- OSTI ID:
- 6889179
- Report Number(s):
- PB-87-113932/XAB; BM-RI-9027
- Resource Relation:
- Other Information: Library of Congress catalog card no. 85-600351
- Country of Publication:
- United States
- Language:
- English
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