Ive been considering different foundation types for a frame house. No soil investigation has been done so far. The water is very close to the surface if you dig a hole it fills with water immediately. In which code can I find information on the proper geological investigation procedure and choice of foundation based on that? In the international building code I couldnt find it; also it addresses only slab on grade and spread footing types of foundation and does not say anything about helical piles, concrete cast in place piles. Why?
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You might start with your county building permit office -- see what options they will issue permits for.
Prescriptive Codes
Building codes usually address prescriptive requirements for the most fundamentally conventional construction methods used under basic circumstances. Others are addressed in the code by desired outcome i.e. what forces and circumstantes need to be accounted for. How this is accomplished is up to the designer. Calculations are the way this is accomplished. You need to consult a geo-technical engineer for soils evaluation. The code won't specify the procedure. The evaluation will determine the circumstances that need to be considered by the design.
No permits are required. Ill have to be the designer, engineer and builder all in one. My location is very cold (freezing depth 1.8 m), this means any shallow foundation (slab, strip) needs to be insulated. An alternative to this would be piles below the freezing depth(not affected by freezing heave forces). People have much objection against shallow piers even for accessory structures because of uneven settlement. Just recently I read that if the water table is high(which is probably my case) the water may flow under a pile (esp if its end bearing, not friction), the pile could suddenly collapse followed by all others along with the whole building; on the other hand in normal soil advantage of bearing capacity of deeper strata can be used with such piles. How can I account for this? Ive been reading some on construction, reinf concrete design; I have a book mechanics of soil, however I cant come up with a uniform step by step procedure for this(and Ill have to do that by myself without geotechnical engineer) Could you recommend some university textbooks as well as official documents I can refer to?
At the risk of sounding like someone else here, hire an engineer.
beautiful!
Bingo, Dan.
You've just gone and hit the nail right on the head.
No Permits.
If no permits are required, that's all the more reason to hire an engineer. If you do it yourself who will make sure you've done it right? Not the building department. Nature. When nature tells you you've done it wrong, you're screwed.
I third the nomination for an engineer...
Interview several with the information you have...someone in your general area should be familiar with your issues. They may (and likely will - since you will also be asking them to take on the liability for the design) ask you to hire a geotechnical engineer as well. The geotech will give recommendations for design and outline the soil capacities, depth of footings, etc and the engineer will put the work together along with the rest of the structure (beams on pilings, floor structure, shear transfer, etc.).
Even if you have a building department, they only review work and likely would want to see an engineers stamp...
oops
sorry.