An evaluation of repeated loading of a transverse stress laminated wood bridge deck

Abstract

This report deals with an innovative type of bridge deck that was introduced in Ontario in the late seventies, a stress laminated wood bridge deck. Popularized in Ontario and the United States, it has become widely used in wood deck rehabilitation projects and has also been found to be a lightweight and economical alternative to steel and reinforced concrete bridge decks. This type of deck uses timber laminates, held together by tensioned bars, as the main structural elements of the deck. It not only provides a comparatively economical and lightweight decking material, but it also supplies good load distribution characteristics and capacity to meet modern needs. The following is an evaluation of a model stress laminated wooden bridge deck subjected to repeated loading. The scope of the project includes designing, building and testing a model of a wooden stress laminated bridge deck in a fashion as to best resemble the repeated loading that might occur over the life time of a real bridge deck. Although the model deck has no real scalable relation to actual bridge decks, the results obtained within the report can still be expected to resemble actual decks. The data found from the testing is used to determine what effects repeated loading may have on the capacity' and lite expectancy of a wooden bridge deck of this nature. More specifically the report deals with the affect that the loading has on displacements within the model deck and on stressing forces in the stressing bars that hold the deck together.