Transfer mechanics of full-column resin-grouted roof bolts.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9336, 1991 Jan; :1-14
The U.S. Bureau of Mines conducted a laboratory investigation designed to evaluate the stress and deformation characteristics of fully grouted roof bolts subjected to various magnitudes of end loadings. The experiment and subsequent analysis were completed, utilizing axial deformation data obtained ultrasonically from forty- one 4-ft, grade 40 roof bolts, with a total of 132 measurement locations along the lengths of the bolts. The ultrasonic measurement instrumentation used in this investigation allowed for elongation measurements without requiring extensive bolt modifications. The results indicate that approximately 39 pct of the applied end load dissipated within the first 3.4 In of the bolts. However, only 3 pct of the applied load was realized beyond 28 in of the grout column. Data are presented individually for every 6-in increment of bolt length; analysis was performed using statistical, nonlinear equations developed for 5,000- and 8,000-lb loading conditions.
Measuring-instruments; Loads-Forces; Mining-engineering; Stress-analysis; Experimental-data; Nonlinear-systems; Mathematical-models; Ultrasonic-tests; Deformation; Underground-supporting; Columns-supports; Grouting; Bolts
IH; Report of Investigations
NTIS Accession No.
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 9336