Load behavior of grouted bolts in sedimentary rock.
Proceedings: new technology for coal mine roof support. Mark C, Dolinar DR, Tuchman RJ, Barczak TM, Signer SP, Wopat PF, eds. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2000-151; (IC 9453), 2000 Oct; :73-80
This paper presents an overview of laboratory and field tests on approximately 250 fully grouted roof bolts instrumented with strain gauges in order to study loading behavior. Laboratory work included pull tests, time-dependent tests and shear tests. The field tests were conducted in 14 different mines extracting different commodities. However, because of the focus of this publication, only the results of tests in 9 coal mines are reported here. In the field tests, all but 14 bolts were loaded by rock movement; these 14 bolts were tested using pull gear. The variables studied included anchorage length, mechanical interlock, time-dependent behavior, shear, installation load, loading rate, and maximum load level. Such information will improve the understanding of the behavior or resin-grouted bolts, which in return will enhance the safety of miners by reducing the occurrence of rock falls. The influences of geology, overburden depth, entry width, mining-induced stresses, and bolt spacing are not described.
Coal-mining; Structural-analysis; Mine-shafts; Accident-potential; Accident-analysis
Mark-C; Dolinar-DR; Tuchman-RJ; Barczak-TM; Signer-SP; Wopat-PF
Information Circular 9453 - Proceedings: New Technology For Coal Mine Roof Support