Strength of log bridge stringers after several year’s use in southeast Alaska

Russell C. Moody; R.L. Tuomi; W.E. Eslyn; F.W. Muchmore

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Strength of log bridge stringers after several year’s use in southeast Alaska

Informally Refereed

Authors:

Russell C. Moody, R.L. Tuomi, W.E. Eslyn, F.W. Muchmore

Year:

1979

Type:

Research Paper

Station:

Forest Products Laboratory

Source:

Research Paper FPL-RP-346. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 4 pages

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Download (PDF 59 KB): https://research.fs.usda.gov/download/treesearch/22196.pdf

Abstract

Bending tests of 28 untreated log stringers from 12-year-old native timber bridges in southeast Alaska showed significant reductions in strength due to decay. Compared to results on fresh logs, strength reduction was about 25 percent, and could be predicted based on the loss in section modulus due to decay. Log stiffness was not significantly affected. Results will be helpful to engineers with responsibility of rating the load capacity of bridges having untreated log stringers.

Keywords

Picea sitchensis, roundwood, logs, strength, wooden bridges, stringers

Citation

Moody, Russell C.; Tuomi, R.L.; Eslyn, W.E.; Muchmore, F.W. 1979. Strength of log bridge stringers after several year’s use in southeast Alaska. Research Paper FPL-RP-346. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 4 pages