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Author
Kovacs, W. D. | Salomone, L. A. | Yokel, F. Y.
Title
Comparison of Energy Measurements in the Standard Penetration Test Using the Cathead and Rope Method. Final Report. Phase 1 and 2.
Coporate
National Bureau of Standards, Washington, DC
Sponsor
Nuclear Regular Regulatory Commission, Washington, DC
Report
NBSIR 83-2760; NUREG/CR-3545, November 1983,
Distribution
Available from National Technical Information Service
Contract
NRC-FIN-B7457
Keywords
percussion drilling rigs; penetration tests; cable tool rigs; hammers; drill strings; potential energy; kinetic energy | time measurement
Abstract
Studies conducted on the Standard Penetration Test (SPT) and its present use in engineering practice show that a wide variation in the use of different pieces of SPT equipment, procedures and personnel results in a range of energy measured in the drill rods from 30 to 85 percent of the standard SPT energy. The potential energy and kinetic energy of the hammer were measured prior to impact, and the energy passing through the drill rods was calculated from a force-time measurement in the rods. It was found that safety (type) hammers tend to allow more kinetic energy to pass through the hammer-anvil system than donut (type) hammers. The energy passing through the drill rods was calculated by using a digital processing oscilloscope and an SPT Calibrator. Lessons learned in evaluating the energy measurements by these two methods are discussed.