Another Insulated Raft query - heavy loadings/basement design - show us your ring beams!

[Conor]

We're struggling to get a designed finalised that can take the wall loadings from our house - basement plus 1.5 stories above - ICF.

 

This is the current design (100mm slab, 300mm ring beam, loads of rebar) but apparently the load transfer from the concrete ring beam to the EPS300 is just outside the safety margin allowable. Engineer is coming back this afternoon with some alternatives. Ranging from extending a toe out, thicker concrete slab, more rebar to transfer load to main slab.

 

Does anybody have examples of what they did for similar scenarios?

[mvincentd]

I imagine only a SE with knowledge of all your factors can help really.  I notice that detail doesn’t show any rebar in the wall tying into the slab.  I guess this isn’t just a case of designing the slab to suppport the house, but using the slab to assist the (retaining) basement wall in resisting the ground and whatever surcharges are on it.

So I can’t see it being much use to you but here’s my ‘not entirely dissimilar’ scenario;
section cc for example, wall is fully basement and supports 1 storey of block work cavity wall out of the ground above....it’s only 350 thick to provide the base width for that cavity wall makeup and not for structural necessity.

section bb is only 225 thick wall and is not supporting any further storeys, but the full height is retaining.

Im on undisturbed chalk dug down to between 1 and 4 metres.

Hope something here helps a bit.

 

16440 rc01 e.pdf