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Development of a TL-2 Steel Bridge Railing and Transition for use on Transverse, Nail-Laminated, Timber Bridges




Ryan Terpsma, Ronald Faller, John Reid, Dean Sicking, Bob Bielenberg, Scott Rosenbaugh, Karla Lechtenberg, Jim Holloway




A previously designed and full-scale vehicle crash tested, thrie beam and channel bridge railing was adapted for use on transverse, nail-laminated, timber deck bridges used by the West Virginia Department of Transportation. The original bridge railing and transition systems were developed and crash tested for transverse, glue-laminated, timber decks using the Test Level 2 (TL-2) requirements found in NCHRP Report No. 350. For this study, the steel bridge posts and post-to-deck attachment hardware were fastened to the new timber deck. Four dynamic bogie tests were used to evaluate the structural capacity of the steel hardware as well as the timber deck. The use of timber shear connectors was evaluated in two of the four tests. For all of the tests, the bridge posts were plastically deformed, bent backward, and twisted. No rupture was observed in the steel bridge hardware or within the timber deck. Timber deck damage consisted of slight bearing deformations surrounding a few of the vertical bolt holes. The timber deck, posts, and post-to-deck attachment hardware withstood peak impact loading and provided sufficient structural capacity to support the TL-2 thrie beam and channel bridge railing system. Although the timber shear connectors reduced the minor bearing deformations, their use was not deemed necessary for actual bridges.


Highway Safety, Bridge Post, Bogie Testing, Transverse Timber Deck, TL-2, Nail-Laminated Deck, NCHRP 350, Thrie Beam Bridge Rail, and Roadside Safety

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