- Author
- Kovacs, W. D. | Salomone, L. A. | Yokel, F. Y.
- Title
- Energy Measurement in the Standard Penetration Test. Building Science Series (Final).
- Coporate
- National Bureau of Standards, Washington, DC
- Report
- NBS BSS 135, August 1981,
- Distribution
- Available from National Technical Information Service
- Keywords
- subsurface investigations | penetration
- Abstract
- Geotechnical engineers in the United States commonly use the Standard Penetration Test, SPT, in subsurface investigation for routine foundation designs. It has been said that perhaps up to 80 to 90 percent of the routine foundation designs are accomplished by the use of the SPT 'N' value. Despite efforts to standardize more details of the SPT procedure, variability between tests is inherent under present guidelines. A field measurement system and procedure which measures the energy delivered by a drill rig system were developed and successfully used to study the factors which affect delivered energy. Results are presented which indicate the energy delivered by certain drill rig systems used in engineering practice. Also, the transmission characteristics of certain hammer/anvil systems are examined. Guidance on the need to measure the actual fall height of the hammer during the Standard Penetration Test is provided based on the findings of the study.