Design and full-scale tests of a-frame timber oak bridge

Pennsylvania Bureau of Forestry Bridge No. 35 was designed to be an economical, low-maintenance timber bridge. It was intended to meet the needs of the owner with regards to cost, aesthetics, and type of traffic. Although the owner only specified that a hardwood timber bridge be built to replace the existing steel stringer bridge, this bridge was designed to be cost competitive with prestressed concrete bridges intended for the same traffic requirements. In addition to low cost, the other important feature is the structural redundancy designed into the bridge in accordance with state and federal requirements. Load tests showed maximum actual live load deflections that were 1.7 times less than the AASHTO-specified maximum allowable live deflection. The cost of the superstructure was $295 per square meter.