獨木橋
獨木橋是由單根樹幹或木板製作成的簡易木製梁橋[1]，是人類最早發明的橋梁，主要用來讓步行者或牲畜跨越較窄的河流和峽谷[2]，通常在能就地獲得木料但難以進行土木工程作業的偏遠山地和叢林地區十分常見。
獨木橋因其長度和寬度限制，通行能力十分有限，而且因為木料會受到風化和生物（真菌和木食性動物，如白蟻等昆蟲）的侵蝕，通常使用壽命也較短[3]。如果使用經過化學加工處理的木料，並在兩端接觸地面的支柱位置採用排水較好的增高地基，則可以顯著延長其使用壽命[4]。
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斯洛伐克天堂國家公園里裝有踏板的獨木橋 -
參考
[編輯]- ^ National Parks Conference, Department of the Interior. Proceedings of the National parks conference held at Berkeley, California March 11, 12, and 13, 1915. Washington: Government Printing Office. 1915: 60 [March 14, 2010].
(A log bridge) is a bridge composed of log beams, the logs being in natural condition or hewn, which are thrown across two abutments, and over which traffic may pass.
- ^ Bennett, David. The history and development of bridges. Ryall, M. J.; Parke, G.A.R.; Harding, J.E. (編). The manual of bridge engineering (Google books). London: Thomas Telford. 2000: 1 [March 14, 2010]. ISBN 978-0-7277-2774-9.
- ^ National Parks Conference 1915, p. 59. "The chief objection to a log bridge ... is the shortness of its life."
- ^ National Parks Conference 1915, p. 59. "If we can design the abutment so that no moisture can collect under the logs the life of the bridge is materially increased."
