Covered Wooden Bridges: A Modern Analysis at the System and Component Levels

摘要

The objective of this paper is to describe the experimental and computational research performed on two covered wooden bridges that were selected as part of the National Covered Bridges Recording Project, sponsored by the Historic American Engineering Record and the Federal Highway Administration between 2002 and 2004. Our work highlights the importance of tension splice joints, or scarf joints, common in the lower chords of covered wooden bridges. The first part of the paper discusses the use of fullscale field measurements of the bridges under live load and the subsequent comparison of those results with two-dimensional computational models of the bridges. An outcome of the full-scale field measurements was the experimental and computational work performed on individual, replicated scarf joints from the bridges, which is discussed in the second part of the paper. It was found that details of the scarf joints, particularly grain orientation, play a key role in their behavior.