Backfilling with sand obtained from desert

[Jas81]

what are the steps to backfill building foundation with sand obtained from the desert
the foundation depth is 1000 mm , our pln is to backfill 800mm by sand and 20mm by sand cement
for the 800mm, shall we backfill in layers and shall we flood the layers by water?
thanks

 

[EireChch]

We had a similar request to use dune sand for an embankment, this was our response. A lot if applicable to your situation. You are likely compacting in a narrow trench so you have good confinement. Desert sand should be fine. Compact it as if it were normal sand.

Compaction of aeolian sand - It is considered likely that the railway embankment core shall be constructed
using dune sand throughout DMC. This material has a single size grading curve which can cause issues when
compacting the layers. The material can also have a relatively flat OMC-MDD curve meaning that the
addition of water does not significantly improve the density achieved during compaction. The use of Gatch
(or similar) confinement bunds either side of the railway embankment should be considered by the Design
and Build Contractor. These bunds help to restrict the dune sand during compaction and a higher density can
be achieved. Once the embankment is completed, the bunds can be trimmed to leave in place a protection
"bank grade' layer to the slope. It is therefore recommended that the material used for the confinement
bunds meets the requirements of bank grade as per the Earthworks Specification.

 

[LittleInch]

What exactly are you backfilling?

Got a drawing?

Also "Desert Sand" is a very wide description. It often contains quite a lot of plant material, Salt and very rounded grains which don't like sitting in one place - which is why it is in the desert.

Now if you dig a big deep hole then you might find better sand, but if you are literally scraping it off the surface then it can be like dust.

Is it just filling a void or what sort of load are you putting on top of it?
Is there any protection from the wind?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[cvg]

step 1 - geotechnical investigation to characterize the "desert sand"
step 2 - ask the geotech for a recommendation based on the field and lab testing

i live in the "desert"
just about everything is silt and sand, but not dunes
everything is compacted in lifts
flooding is never used, jetting is sometimes used
what is the purpose of the soil cement?