A laboratory test program was conducted on full-scale specimens replicating the main elements of a timber trestle railroad bridge chord. Previous field load testing had been done and was complicated by differing site-specific conditions. The purpose of the ongoing laboratory study described herein is to compare field test results with controlled laboratory tests. A three-span bridge chord similar to that of the field bridge was constructed. It was then disassembled and reassembled into a two-span, and then into a one-span, specimen. Load testing was conducted on each specimen to examine the service load behavior of the specimens. Single-point and two-point loadings were used to simulate single and double axles of trains. Comparisons were made between the laboratory results, elementary analytical beam models, and a semi-continuous beam model. Unintended uplife occurred at the supports in the laboratory test set-up. Analytical modeling was modified to reflect this and improve predictions of the response. Additional laboratory tests are recommended on a specimen with support conditions modified to eliminate the uplift.
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