[雙語(yǔ)翻譯]--港航外文翻譯--海洋生物造成的木樁惡化的評(píng)估（原文）

1、Assessment of Wood Pile Deterioration due to Marine OrganismsRoberto Lopez-Anido, M.ASCE1; Antonis P. Michael, S.M.ASCE2; Barry Goodell3; and Thomas C. Sandford, M.ASCE4Abstract: In this paper a description of the major

2、groups of marine organisms causing significant wood pile damage is presented. These organisms are divided into two groups: ?1? fungi and ?2? marine borers. The basic physical and biological characteristics of these organ

3、isms are presented, as well as the type of damage that they cause in marine wood piles. The objective of the study presented in this paper is to characterize deterioration of wood piles due to marine organisms and to ass

4、ess damage in the wood pile zones of a typical waterfront installation. Marine borer activity in Maine coastal waters is assessed through a survey directed to harbor masters; the results of the survey are correlated with

5、 historic data. In order to illustrate the type and extent of wood pile deterioration, two case studies in Maine harbors are presented.DOI: 10.1061/?ASCE?0733-950X?2004?130:2?70?CE Database subject headings: Piles; Wood;

6、 Fiber reinforced plastics; Fiber composites; Wooden structures; Deterioration.IntroductionThe problem of deterioration of wood piles due to marine organ- isms dates back to the historic use of wood in piers and other wa

7、terfront facilities. Even though wood pile deterioration has been mitigated to some extent with the use of preservative treat- ments, it still remains a concern. Some of the chemicals used for wood preservation have been

8、 linked to human health concerns and, therefore, their use has been restricted. For these reasons, waterfront owners are looking for alternative solutions for wood pile protection. There are two major groups of organisms

9、 that deteriorate wood in waterfront structures. Wood degrading fungi generally attack above the water-line region where adequate oxygen allows them to survive and decay the wood. Marine borers attack a va- riety of wood

10、 substrates but are only found in marine environ- ments. Some marine borer species are not of concern from the standpoint of marine piers and waterfront facilities, but aggressive attack by these organisms will occur par

11、ticularly in temperate marine waters. These two groups of organisms attack the wood indifferent zones of a waterfront pile. Fungi are typically found above the waterline, while marine borers primarily attack wood that is

12、 submerged or in the tidal zone. Wood-boring organisms found in saltwater that cause damage to wood piles can be classified as: ?1? molluskan borers ?ship- worms and pholads?; and ?2? crustacean borers including multiple

13、 species commonly known as gribbles ?Goodell 2000?. Both ship- worms and gribbles attack the wood piles for shelter and, at least in the case of shipworms, wood can also be digested through the aid of microbial symbionts

14、 ?Goodell 2000? to supplement filter feeding nutrition. Studies conducted in Maine over a period of 23 years ?1936– 1959? using wood test boards revealed problems associated with shipworms during certain years and at spe

15、cific geographic loca- tions ?Wallour 1959?. Limnoria spp. were present in Maine waters every year during the period studied and caused significant dam- age. Understanding the cause and characterizing the extent of wood

16、pile deterioration is the first step in designing a repair method for damaged piles, as well as in devising a protection strategy to prevent further attack from marine organisms. For example, a system for structural rest

17、oration of wood piles with fiber rein- forced polymer ?FRP? composite shells was designed based on this ap- proach ?Lopez-Anido et al. 2004b?. This system provides shear transfer capability between the wood pile and the

18、encasing FRP composite shells, which strengthens the damaged pile portion ?Lopez-Anido et al. 2003, 2004a?. The repair system can also reduce the rate of future deterioration by introducing a barrier that protects the wo

19、od pile from marine borer attack. The objective of the study described in this paper is to char- acterize the deterioration of wood piles due to wood deterioration organisms and to assess damage in the microenvironment z

20、ones of a typical waterfront installation. An early study of marine borer activity in Maine waters is reviewed. The results of a recent sur- vey of wood pile deterioration in Maine harbors are discussed. Two case studies

21、 in Maine harbors that illustrate typical gribble and shipworm damage are presented.1Assistant Professor, Dept. of Civil and Environmental Engineering and Advanced Engineered Wood Composites Center, Univ. of Maine, Orono

22、, ME 04469-5711 ?corresponding author?. E-mail: rla@maine.edu 2Graduate Research Assistant, Civil and Coastal Engineering Dept., Univ. of Florida, Gainesville, FL 32611. 3Professor, Wood Science and Technology and Advanc

23、ed Engineered Wood Composites Center, Univ. of Maine, Orono, ME 04469-5711. 4Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Maine, Orono, ME 04469-5711. Note. Discussion open until August 1,

24、2004. Separate discussions must be submitted for individual papers. To extend the closing date by one month, a written request must be filed with the ASCE Managing Editor. The manuscript for this paper was submitted for

25、review and pos- sible publication on August 1, 2002; approved on March 19, 2003. This paper is part of the Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 130, No. 2, March 1, 2004. ©ASCE, ISSN 0733-

26、 950X/2004/2-70–76/$18.00.70 / JOURNAL OF WATERWAY, PORT, COASTAL AND OCEAN ENGINEERING © ASCE / MARCH/APRIL 2004J. Waterway, Port, Coastal, Ocean Eng. 2004.130:70-76.Downloaded from ascelibrary.org by Changsha Univ

27、 Of Sci all rights reserved.?up to 60–70 mm? and their diameters are up to 25 mm. The tunnel opening can often be smaller than the diameter of the borer ?Chellis 1961; Goodell 2000?.Crustacean Borers: GribblesLimnoria l

28、ignorum is one species of Limnoria spp., which are also known by the common names ‘‘gribbles’’ and ‘‘sea lice.’’ Gribbles resemble the wood louse and have a length between 3 and 6 mm. Their width ranges from one third to

29、 one half of their length. They are often slipper shaped with horny boring man- dibles, two sets of antennae and seven major sets of legs. Their legs are equipped with sharp hooked claws to grip the wood. Gribbles can ro

30、ll themselves into a ball, swim, crawl, and jump ?Chellis 1961?. Gribbles can swim throughout their lives and they can leave or be dislocated from wood being attacked and return totunnel at another location. They commonl

31、y attack in coastal re- gions making shallow burrows in the surface of the wood ?Johnson 2002? as shown in Fig. 4. When large numbers of gribbles attack, only a thin layer of wood is left between the burrows. The action

32、of the waves and tidal currents wash away these thin layers exposing new surfaces for the gribbles to attack. This causes extensive thinning of the wood section. In wood pil- ing, the damage caused by gribbles is typical

33、ly greater in the tidal zone ?Chellis 1961?.Damage Zones in Wood PilesWood piles that support piers or other marine structures are driven into the mud and extend above the waterline to the deck or struc- ture they suppor

34、t. The vertical variation of exposure conditions of the wood pile has previously been delineated into different mi- croenvironment zones by the U.S. Army Corps of Engineers and allied organizations ?U.S. Army Corps of En

35、gineers et al. 2001?. The microenvironment variation affects the type and the extent of damage produced by marine organisms. Wood pile damage at the mudline observed in Portland Harbor, Me., is shown in Fig. 5?a?. A typi

36、cal damage profile in the different zones of a woodFig. 4. Limnoria spp. damaged woodFig. 3. Typical shipworm damage, Belfast, Me.Fig. 5. ?a? Wood pile at mudline in Portland Harbor, Me.; ?b? typical damage profile of wo

37、od pile72 / JOURNAL OF WATERWAY, PORT, COASTAL AND OCEAN ENGINEERING © ASCE / MARCH/APRIL 2004J. Waterway, Port, Coastal, Ocean Eng. 2004.130:70-76.Downloaded from ascelibrary.org by Changsha Univ Of Sci all rights