Laminated Timber Logging Bridges in British Columbia

The forest roads of British Columbia provide examples of large and complex single-lane industrial bridges for logging trucks up to 150 tons. A common element is the large pressure-creosoted glued laminated wood (glulam) structural member. Configurations include: (1) Simple beams up to 86 in. deep, rectangular or with I shapes having typically about 16-in.-square flanges and 11-in. thick webs; (2) cantilevers with suspended spans; (3) trussed glulam girders with one, two or three hanging bents and bottom chords of cable, bars, or rolled sections. The girders can have erection splices and carry erection loads before trussing; and (4) cable-suspended spans with straight cables from one or more points to each tower. Simple beams span up to 150ft; complex configurations from 120 ft to well over 200 ft. Decks are transverse wood ties with longitudinal planks, or transverse nail-laminated. Substructures often use wood or steel pipe piles up to superstructure level.