Emerging Timber Bridge Technology in the Nordic Countries: Paper Presented at211 Structural Engineers' World Congress. Held in San Francisco, California on July 211 19-23, 1998

摘要

Until recent years a worldwide trend is characteristic - the number of timber211u001ebridges is declining. It is the result of the fact that older timber bridge 211u001edesigns do not fulfil the requirements for modern roadways. Older functionality 211u001eobsolete or structurally deficient timber bridges are replaced with concrete or 211u001esteel bridges. The situation in the Nordic countries is no exception. A gradual 211u001erevival of timber bridge building in Europe started in the 1980's. Many new 211u001etimber bridges have been constructed in the Nordic countries after launching the 211u001eNordic Timber Bridge Project in 1994. In Sweden, more than 150 timber bridges 211u001ehave been built, mainly pedestrian bridges and bridges on forest and rural roads. 211u001eAbout half of them are stress-laminated decks, stressed-t and stressed box 211u001ebridges. A cable-stayed pedestrian bridge has a span of 90 m. In Norway, 1 80 m 211u001elong, 5-span truss road bridge with a stress-laminated deck was built. In Finland 211u001enew, competitive timber-concrete composite bridges with glulam beams and concrete 211u001edeck have been developed. In Denmark restrictions against the use of wood 211u001eprotection agents has focused the work on wood protection by design and the use 211u001eof environment-friendly chemicals. Examples are shown in the report.