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-   -   Need wind load to be calculated (https://www.askmehelpdesk.com/showthread.php?t=363723)

  • Jun 11, 2009, 04:34 AM
    Fenceguy
    Need wind load to be calculated
    I am working on a project that I will need some help with.
    I need to attach chain link fence to the side of a concrete pillar where the fence will be 10' above the pillar and 2' on the side of the pillar for a total of 12' high.
    The fence will be of what is called louver-mesh meaning that the opening of the chain link will be 6%. The customer tells us that we need to figure posts to withstand 110 miles per hour.

    What size posts will I need to support this?
  • Jun 25, 2009, 10:46 AM
    jcaron2

    Some questions:

    -What material will you be using for the posts? I think high strength 83K-grade Schedule 40 steel pipe is typical.
    -What post spacing are you trying to achieve?
    -Will there be any potential icing on this fence?
    -What exposure category is this, B, C, or D, as defined below?

    Exposure B: Urban and suburban areas, wooded areas or other terrain with numerous closely spaced obstructions having the size of single-family dwelling or larger.
    Exposure C: Open terrain with scattered obstructions having heights generally less than 30 feet (9.15M). Includes flat open country, grasslands and all water surfaces in hurricane prone regions.
    Exposure D: Flat, unobstructed areas exposed to wind flowing over open water for a distance of 1 mile (1.61 km) outside hurricane prone regions. Includes smooth mud flats, salt flats, and unbroken ice.
  • Jun 25, 2009, 11:22 AM
    jcaron2

    Better yet, just read through this publication:

    http://filelibrary.associationsites....tion/WLG08.pdf

    Since 2' of the total fence is in line with the top of the pillar, your effective height for purposes of the post calculation should be 10'.

    Your mesh is only 6% open, meaning that it's 94% solid. Therefore, the fabric mesh coefficient, Cf1, in your case will be . The wind exposure category coefficient, Cf2, will be 1.00 for exposure category B, 0.67 for C and 0.55 for D. The Ice Exposure coefficient will be 1.00 for no icing, 0.85 for regions subject to moderate icing, and 0.45 for regions prone to heavy ice storms. With that information, you should be able to just look up the maximum allowable spacing for various types of posts in Table 5. Just make sure you calculate your actual spacing as

    S' = S (from the table) * Cf1 (1.06 in your case) * Cf2 * Cf3

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