Earth backfill in layers between a concrete structure and sloped cut(1:2)

[Good_Guy]

I am seeking the best way to backfill between a concrete structure and the sloped cut

I have attached an approximate sketch. The requirement is compacting the backfill in layers not more than 300mm

The width of placment is approx 2m at the base and the height

The length of the backfill is about 20 metres

The contractor is almost placing at layers of 300mm but has done for only 9 metres and has almost created a vertical joint for the balance of placement(11 metres)

Can such a steep joint be created for earth backfill?

I hope I am clear..please see the sketch

 

[oldestguy]

Big question. What earth density, lateral pressure on the structure is it designed for? Too much compaction of backfill against the structure may cause an overloading that the structure may not be designed for. Under some situations the pressure developed can be kept tolerable by not compacting on that zone one meter or more next to the structure.

 

[jdonville]

Per oldestguy's comment, NAVFAC DM 7.2 has some discussion on compaction stresses.

2m is (relatively speaking) a fair bit of room between the temporary slope and structure. Normally we provide 3ft/~1m clear - just large enough for a man to install and remove forms.

 

[jdonville]

EDITED

Sorry, missed your original question entirely on that compaction stress tangent.

It is usually not desirable to create a near-vertical scarp like that if for no other reason than it is now a potential engulfment hazard to those who will need to fill adjacent to it. It is really confusing as to why the contractor placed fill in that geometry. I would have expected that at the least, the scarp would be perpendicular to the concrete wall. (Also, I doubt that the soil at the "edge" was compacted to the same degree as that located between the structure and cut face.)

It will now be difficult to compact anything in the narrow area between the scarp and the temporary cut face. You will likely need to place flowable fill in this narrow area.

 

[Good_Guy]

Thank you all for the valuable comments