Method and Apparatus for In Situ Evaluation of Wooden Members

Agency:

Forest Service

The invention is a nondestructive way to evaluate the integrity of the entire length of structural-wood components from one end. This includes those portions beneath the soil or water line, or which are otherwise inaccessible. This is valuable because structural-wood components have a variety of applications in pilings for foundations, utility poles, and supports for guard rails. The invention uses acoustic waves directed from the free end, to reflect off the embedded end of the wood, to be measured at the free end. The reflection occurs because of the discontinuity between the wooden member and its surroundings. The time required for the reflection of the acoustic wave is compared to a reference speed to calculate the integrity of the wooden component. Laboratory and field tests of the method accurately determined the integrity of structural-wood components of various types which were partially embedded in soil. Wooden supports embedded in the soil provide support for loads directed against the free end. These structures are inexpensive but sturdy construction solutions. For example, wooden pilings can carry 15 to 20 tons per piling. However, despite their strength and low cost, wood is subject to weakening from decay, insect infestation, and chemical attack. Prior to this invention, no method or apparatus existed for efficiently and accurately measuring the integrity of a wooden member having only one end inaccessible.

Reference:

Please refer to Patent Number 5,396,799, which issued March 14, 1995.

Inventors:

Robert J. Ross USDA Forest Service Forest Products Laboratory One Gifford Pinchot Drive Madison, Wisconsin (608) 231-9221	Earl A. Geske (Same as first inventor) William J. Nelson (Same as first inventor)
Vyto C. Malinauska (Same as first inventor) Rodney C. DeGroot (retired)	Diego Cuevas (Non-Forest Service)