- Author
- Knab, L. I. | Yokel, F. Y. | Galligan, W. L. | Bendtsen, B. A. | Senft, J. F.
- Title
- Study of Lumber Used for Bracing Trenches in the United States. Building Science Series (Final).
- Coporate
- National Bureau of Standards, Washington, DC Forest Products Laboratory, Madison, WI Purdue Univ., West Lafayette, IN
- Sponsor
- Department of Labor, Washington, DC
- Report
- NBS BSS 122, March 1980,
- Distribution
- Available from National Technical Information Service
- Keywords
- trenching | timbering (supporting)
- Identifiers
- FORTRAN 5 programming language; UNIVAC -1110 computers
- Abstract
- This report presents a study of the properties and characteristics of trenching lumber which are critical to its structural performance. Using these properties and characteristics, allowable stresses and use recommendations are proposed. The National Bureau of Standards (NBS) conducted a field study of trenching lumber and found that either ungraded eastern species, primarily hardwood, or graded Douglas-fir is used. For graded Douglas-fir, allowable design stresses and other properties are established by existing standards. The eastern species, however, are ungraded and no accepted guidelines are used to assign allowable design stresses and other properties.