NDE of Wood Utility Poles Integrating Results of Gamma Densitometrie and of Visual Inspection
Andre R. Taras, Mircea Iordanescu
ABSTRACT (CONCLUSIONS) The properties of wood fiber and the presence of other elements in the pole structure (knots, number of rings, wood decay, inner defects such as shell separations) combine their effects to establish the overall strength of the pole. The proposed integrated inspection method combines the results of several of these pole characteristics through Gamma measurements and visual inspection. This method produced a better performance in evaluating the strength of a pole than with the Gamma instrument alone.
This integrated inspection method has the advantage over the conventional, method (sounding, drilling, visual) of producing a quantitative evaluation of strength. Also, it combines the advantages of measuring the inner condition of a pole along as length with visual detection of external visible defects and other strength reduction factors.
Density measurements along the length of the pole proved to be a fairly good predictor of as structural integrity: for one, R represents an intrinsic strength predictor of the wood fiber independent of wood species; second, it determines the structural weakness along the pole given the occurrence of zones of deterioration in the midst of a stress distribution field along the pole; third, its strength prediction improves for poles with deteriorate conditions.
This method can be incorporated into standard pole inspection practices or in the strength evaluation of any type of round wood structure. Combining the results of pole strength to the service loads applied to the pole can provide a good pole reliability-analysis method. Potential improvements to this integrated inspection method can be envisaged 04. in the following ways:
- developing a greater and more representative pole data base so as to able to segregate the data by species;
- adopting a predictive pole-strength model based on Fuzzy Logic instead of the set of multiple linear regression functions, as was successfully attempted in a previous study [7].
Publication Source: WCTE '98 - 5th World Conference on Timber Engineering, 1998 August 17-20, Montreaux, Switzerland.
Vol. 1, Pages 626.....
Publisher: Presses polytechniques et universitaires romandes - [Homepage]
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