Pre-Designed Timber Bridges of Three Types for Arkansas County Roads

摘要

Well-designed 'modern' timber bridges could be a cost-effective alternative forthe replacement of substandard bridges on county and city roads. Three types of simple span timber bridges have been designed with accompanying specifications for ready use: (1) solid sawn stringers with transverse solid sawn deck planks, (2) glulam stringers with transverse glulam decks, and (3) stress-laminated full-span glulam stringers, all constructed of southern pine (SP). This report contains designs for the first type using 6 different SP stringer sections, for the second type using 4 different standard widths of SP glulam stringers, and for the third type using the same 4 separate widths of SP glulam stringers. Designs focused on flexural adequacy. Procedures are included for changing span length or depth of the primary bending sections to fit with any desired allowable deflection limitation or smaller 'load duration factor.'