Mobile home basements

[metljakt]

I'm a small town PE. I've been asked to design basements for several Mobile Homes. These have nine foot walls. There is approximately eight vertical feet from the interior slab to the outside grade elevation. Soil is coarse sand & gravel. Does anyone know of any publications that wlll assist me in this.

 

[TFL]

1. You have to make sure the top of the wall is laterally supported by the home, otherwise you have to design it as a canted retaining wall.

2. if it is supported by the floor of the structure you can design the wall as a simple concrete beam. usually using an equvalent fluid preassure of about 50 pounds per cubic foot

3. if you don't to do the calcs the internation building code 1 and two family edition has prescriptive requirments.

 

[SirAl]

Try this link

http://www.jlconline.com/cgi-local/view.pdf/8a42973df1ab3de667e78d501243cb88/

http://www.jlconline.com/cgi-bin/jlconline.storefront/3fad53600014ff49271a401e1d2905e7

If it does not work, find thread256-77803 and scroll to a Nov 8 post by VBI who provided the link. (I just tried it and got the article).

 

[Cthornton]

Is the basement directly under the mobile home? How will the mobile home be supported? Typical supports (blocks) under mobile homes I have reviewed are 6' centers unless manufactures specs require other.

 

[metljakt]

Terrific response from the three of you! I read the Anderson article & several posts which call out =fluid pressure for my soil type as 30pcf - some say too low. Anderson states that typical wall failure is due to consolidation of fines. I've got less than 5% passing a number 200 sieve. I guess I could go with 50lbs as proscribed by tfl. I want to thank you for these responses.

 

[TFL]

I know my 50 lbs is pretty conservative. however, when giving advice on how to do it quick and easy with out knowing where you were i thought i would use a big number

 

[LUGuy]

I ran into a couple of mobile home foundation issues lately with loan approvals. Searching the appendix of the IRC led me indirectly to the Permanent Foundations Guide for Manufactured Housing, document #4930.3G, as published by HUD. This link should bring you directly there:

http://www.hudclips.org/sub_nonhud/cgi/hudclips_run.cgi?hudclips_run

I heard somewhere recently that all manufactured housing design falls under federal guidelines. I don't know if this is true and I don't know if this is THE document to go by. And I doubt even more that it is enforced.

However, the two requests I had about "certifying" that foundations were designed to "code" had me wondering if they even knew what they were asking for, and which code they really meant. Was it the federal HUD code, or the IRC? Fortunately they were both no-brainers by virtue of being set freely on hollow masonry blocks with no attachment, and therefore not being compliant with any design standard or code at all.

Regards,
Miscmetals

 

[metljakt]

I believe its HUD. Here's the document I downloaded:

http://www.huduser.org/Publications/PDF/foundation_guide_complete.pdf