Settlement in backfill by column bases

[BauTomTom]

Hallo

I have the such an case (see attached sketch at best) where my column bases are around 2m deep. This needed of course be backfilled, in layers 150mm and each compacted to 98% MODASHTO
On top I requested a DCP test just to make sure, that all layers were properly compacted.
Now the DCP test results give me such irregular levels so that I am confuse what to do.
The layers differ from 50kPa up to 400kPa
And the curve is just a zick zack.

How critical must I see the compaction of this backfill?

I know the contractor compacted it but it seams like not really properly or maybe not even every layer, or the layers were to high

Bau Tom Tom

 

[BauTomTom]

TO CSD72:

only 0.1MPa? sounds little. This is 100kN/m² hhmm... ok for a surfacebed should be really enought actually.

I wonder why I can't use the DCP results and see where everywhere where this 0.1MPa is not reached at least it woudl be for me an indication of higher sattlement and consequently the compaction is nor well done and rejected

TomTom

 

[csd72]

compacted fill can still settle

 

[BauTomTom]

Ok guys

I think this toppic was also very particular discussed and it definately helped me further.

Thanks a lot to you all ;-)

BauTomTom