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Anonymous Poster

Test Strength of Poles

10/04/2010 9:01 PM

I have a marina with a covered harbour. I am needing to redo the skin of it but thought about putting cabins over the top of each slip. There are currently 20 slips with 80 -10" diameter poles in the water that support the structure. Each cabin would only be 32 x 12 and very basic. How can I determine or who should I talk to in order to find out the strength of the existing structure? Thanks for any help.
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dvmdsc
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United States - Member - New Member

Join Date: Mar 2010
Location: Bahamas
Posts: 1962
Good Answers: 97
#1

Re: Test Strength of Poles

10/04/2010 9:56 PM

With that little info I would strongly advise to put no more than a tent structure on it. What are the poles made of? How many @ what distance? What is the substructure? Weight already on the poles? Underground, foundation, pore water tension, length? You will really need to talk to a structural engineer, who is very familiar with the area. Why not make some drawings and photos and submit these here?

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Atlantis
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Anonymous Poster
#2

Re: Test Strength of Poles

10/05/2010 12:23 AM

Will do . I registered but waiting on confirmation email. Please understand the drawings are done on MS paint and only a "idea on a beer napkin". I will post tomorrow along with the current actual dims and what I forsee the new dims being.Just trying to find out if this is even worth the effort.

Cwheed
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Anonymous Poster
#3
In reply to #2

Re: Test Strength of Poles

10/05/2010 10:54 PM

Where will this be located? Most waterways have restrictions as to what you may or may not do.
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Tamu
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Join Date: Mar 2006
Location: Sydney, Australia
Posts: 96
Good Answers: 5
#4

Re: Test Strength of Poles

10/06/2010 12:05 AM

How deep are the poles driven into the substrate?

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Ca-Vin
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Join Date: Sep 2009
Location: Brisbane, Australia
Posts: 91
Good Answers: 3
#5

Re: Test Strength of Poles

10/06/2010 12:54 AM

Basically, you need to calculate the mass of the structure plus allowable live loads (in Mpa or equiv. and convert to a force (Nm or equiv). Calculate the net wind loading (varies with location and terrain category). Allow for max down force and ALSO allow for max uplift and lateral loading. Determine the MINIMUM cross-section of each pole (this may reduce under water due to erosion etc.).

Calculate your total cross sectional area (min pole area x number of poles). Divide the total max download y the total cross section area. Result is the actual stress. Calc the allowable compression stress for the poles (there will be a standard for this). This checks that the poles will not buckle.

Use the maximum upward wind load subtract the live and dead loads and divide by the cross sectional area of the poles. I would recommend keeping the allowable stress to below 66% of the pole materials yield.

Calc the bending moment on the poles by taking the lateral load (L) and multiplying by the length above ground (harbour floor). M = WL. Divide this moment by the second moment of inertia of the poles (pi.d3)/32.

Check you deflection (WL3)/3EI where E is the young's modulus for the pole material and I is the moment of inertia for the section (r) r = d/4.

Now you know why engineers are paid the big bucks.

Best Regards,

Royce R. Vines

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hotwater
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Join Date: Sep 2009
Location: Georgia
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Good Answers: 1
#6

Re: Test Strength of Poles

10/06/2010 1:24 AM

You may find that the Hurricane codes, if you are in that area of the country will be too costly of a build to be cost effective.

In most of the Hurricane area per. square foot costs range into the $250 plus, and must withstand up to 500 mph winds.

Quick cost per slip unit would be in the $100,000 + as a guess.

As for an estimate use the most expensive contractor numbers to plan your budget on, it is better to over budget than under budget.
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rcapper
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Join Date: Dec 2005
Location: Etats Unis
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#7

Re: Test Strength of Poles

10/06/2010 6:28 AM

Hire a licensed and insured architect.

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Doorman
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Hobbies - DIY Welding - New Member, but planning to be an Old Member Popular Science - Weaponology - New Member

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Location: Fargo, America, USA
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#8

Re: Test Strength of Poles

10/06/2010 12:02 PM

The Test Strength of Poles, eh?

Aneta Florczyk started her career at the age of 16, as a powerlifter. She won Polish Championships several times.

This is the woman we see rolling up a steel frying pan on television.

Sorry... could not help myself

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peterg7lyq
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Join Date: Jan 2010
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Good Answers: 60
#9

Re: Test Strength of Poles

10/10/2010 7:44 AM

Piles of information May i suggest you use the links below to aid your research it is important i feel that you should work out how to construct a safe load bearing structure, Although it would possibly be better to get advice from structural engineers

http://www.google.co.uk/search?q=structual+loading+of+steel+piles&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=y6axTMWYJIXy4ga2lpTTBg

http://www.google.co.uk/search?q=how+to+determine+safe+load+of+steel+piles&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=KaexTODhGZ6G4gbipry1Bg

http://www.google.co.uk/search?q=how+to+build+elvevated+living+accomadation+on+piles+above+a+river&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=rqexTMrYOpXa4gbrmLjADw

http://www.google.co.uk/search?hl=en&newwindow=1&safe=off&rls=com.microsoft:en-gb:IE-SearchBox&rlz=1I7GGLT_en&&sa=X&ei=QqixTK-TMtO6jAe-pLxA&ved=0CBcQvgUoAA&q=how+to+dertermine+the+weight+carrying+capacity+of+hollow+steel+piles&nfpr=1

http://www.google.co.uk/search?hl=en&newwindow=1&safe=off&rls=com.microsoft:en-gb:IE-SearchBox&rlz=1I7GGLT_en&&sa=X&ei=baixTOi8Ftq5jAfL67zuBA&ved=0CBcQBSgA&q=how+to+determine+the+weight+carrying+capacity+of+hollow+steel+piles&spell=1

http://www.ralingroup.co.uk/weights.html
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