Re: Re: Architect Registration
The load from that floor is not transferred to to the perimeter foundation. It is transferred down through the insulation to the hardcore. That floor is a straightforward ground bearing floor slab. If the insulation does what is says on the tin, then the stress will be substantially reduced by the time it hits the subsoil. The insulation in that sketch is playing a critical structural role.
No, you never interfere with the soil below the cut, you excavate away from the property on both sides and draw strike lines between the excavation pits to develop a picture of what is going on. The soil beneath the footprint, should always be left undisturbed below formation level.
2.1m is not that safe, if the underside of your foundation is at 1m below ground level, then you only have 1.1m to the water table. You have to have a min. of the same width as your foundation to satisfy building regs. There is a certain area of soil beneath the foundation that gets stressed called the “bulb of pressure”, if it gets wet, then the bearing capacity is significantly reduced, in Sands, the bearing capacity reduces by 50% when wet. Examine the sides of your pit for rusty stains (deposits of iron oxide) they will show you the height of the winter water table.
Not mad about that detail to be honest, it would require gound ground conditions and an excellent structural performance from the insulation, I wonder if those companies ever considered “creep” taking a toll on the insulation. This occurs from long term compression and causes concrete to shrink over time. The concrete is reinforced with extra steel in areas of significant compression.