A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Timber Bridges in Modern Japan
In Japan, timber has been used for not only traditional building but also bridge construction since olden times. At least until the 1950s, various types of bridge were in service, including trestle, truss, suspension, etc. for forest railways. However such timber bridges were replaced with concrete or steel bridges, which were thought to be, and were called, “permanent bridges” in those days. Government policy represented by the Five-Year Plan for Road Construction in 1954 facilitated the replacements, and a large percentage of timber bridges disappeared from Japan. Since the late 1980s, new types of timber bridge, so-called “modern timber bridges”, began to be constructed in Japan. The development of materials such as glulam (glue-laminated timber) with a large section, curved glulam, etc. treated with preservative made it possible to construct roadway bridges with several ten-metre spans. The longest span bridge in Japan is Karikobozu Bridge, which was completed in 2003 and has three king post truss spans (the longest span being 48 m). Construction of modern timber bridges reached its peak around 2000 and decreased significantly after that. As budget allocations for public works projects were decreasing, it became difficult to construct symbolic timber road bridges with higher costs. From the 2010s onwards, new approaches have been tried for timber bridges, utilizing the lightweight properties and easy workability of timber but avoiding high-specification road bridge requiring higher costs. Typical examples are illustrated and recent directions discussed.
Timber Bridges in Modern Japan
In Japan, timber has been used for not only traditional building but also bridge construction since olden times. At least until the 1950s, various types of bridge were in service, including trestle, truss, suspension, etc. for forest railways. However such timber bridges were replaced with concrete or steel bridges, which were thought to be, and were called, “permanent bridges” in those days. Government policy represented by the Five-Year Plan for Road Construction in 1954 facilitated the replacements, and a large percentage of timber bridges disappeared from Japan. Since the late 1980s, new types of timber bridge, so-called “modern timber bridges”, began to be constructed in Japan. The development of materials such as glulam (glue-laminated timber) with a large section, curved glulam, etc. treated with preservative made it possible to construct roadway bridges with several ten-metre spans. The longest span bridge in Japan is Karikobozu Bridge, which was completed in 2003 and has three king post truss spans (the longest span being 48 m). Construction of modern timber bridges reached its peak around 2000 and decreased significantly after that. As budget allocations for public works projects were decreasing, it became difficult to construct symbolic timber road bridges with higher costs. From the 2010s onwards, new approaches have been tried for timber bridges, utilizing the lightweight properties and easy workability of timber but avoiding high-specification road bridge requiring higher costs. Typical examples are illustrated and recent directions discussed.
Timber Bridges in Modern Japan
Gotou, HumihikoDeng (author) / Aoki, YukariPhD (author) / Oikawa, DaisukeMeng (author) / Hirasawa, HideyukiDEng (author) / Sasaki, TakanobuDEng (author)
Structural Engineering International ; 35 ; 118-124
2025-01-02
7 pages
Article (Journal)
Electronic Resource
English
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