good morning we are facing prob

[aboukora]

good morning

we are facing problem at site for achieving the below shell DEP requirement for the tank foundations sand compaction

The first sand layer shall be compacted with a
plate vibrator to achieve a minimum strength or density of 5 MPa or 98 % Proctor.
The thickness of the compacted layer shall not exceed 0.3 m. The sand shall be
placed and compacted at Optimum Moisture Content ± 2 %.

note the sand saving show 99% less than 5 mm passing

if any recommendation how to achieve this value please help

regards

 

[Ron]

I'm confused about your 5mm passing comment....are you saying that very little of the material is smaller than 5mm? If so, that's not sand...it is gravel.

A lift thickness of 0.3m is too thick to be compacted properly with a small plate compactor. Forget the 5MPa requirement and compact to 98% of the Proctor. That's easily tested.

The key to getting compaction will be controlling the moisture content. Keep it as close to optimum as possible.

 

[oldestguy]

If the material is truly mostly larger than 5 mm, I question using any Proctor type test. The compacting is likely to break down the particles and result in a density that is not representative of the site material. I'd use a vibrating table for lab compaction standard compaction and use 90 percent relative density for the job acceptance.

 

[cvg]

we are using a 4 ton vibratory roller in order to get 70 percent relative on sand. 4-8 percent moisture and 8 inch lifts max. 6 inch for vib plate. relative density is very specific to the actual gradation of the sand and test fill is recommended to establish the procedure