Coal pillar strength study (The design of production pillars in coal mines).
Pariseau-WG; Hustrulid-WA; Swanson-SR; Van Sambeek-LL
NTIS: PB 274-900 Available for Reference At Bureau Libraries, 1977; :1-442
Laboratory tests for unconfined compressive strength and young's modulus on 371 test cylinders of coal at length-to-diameter ratios of 1/2, 1, 1-1/2, and 2, and nominal diameters of 1, 2, 4, 6, 8, and 12 inches are reported. Field measurements at 117 closure pin stations and 119 vibrating wire stress gage sites in the vicinity of two 60- by 60-foot test pillars separated by 20-foot entries and crosscuts show approximately 1 to 2 inches closure and 2,000 to 4,000 psi stress change prior to mining of the pillars to failure. Finite element analysis of the test section from development through pillar mining and retreat using laboratory rock properties as input shows good agreement with the measured closures.
Mining; Laboratory testing; Compressive strength; Measurement equipment; Coal mines; Pillar design; Pillar mechanics; Rock mechanics; Environmental stress; Room and pillar mining; Retreat mining
CP; Final Contract Report
NTIS Accession No.
NTIS: PB 274-900 Available for Reference At Bureau Libraries
University of Utah