Per SAES-A-114 Excavation and Backfill:
Soils shall be classified per ASTM D2487.
6.2.1 Fill Material
Fill material shall consist of gravel, sand and/or marl. The maximum
size of the fill material shall be one-half the lift thickness or 75 mm
(3 inches), whichever is less. Fill material shall be free of frozen lumps,
organic matter, trash, chunks of highly plastic clay or other
unsatisfactory material.
6.2.2 Select Fill Material
Select fill shall be composed only of inorganic material and shall have
100% passing the 5 cm (2 in) sieve and from 0 to 20% passing the No.
200 sieve. That portion of the material passing the No. 40 sieve shall
have a maximum liquid limit of 35 and a maximum plasticity index of 12
per ASTM D4318. Liquid limit and plastic limit tests are not required
for select fill material with less than 15% passing the No. 200 sieve.
6.3.2.2 Fill material shall be placed in lifts not exceeding 200 mm
(8 in) in loose depth. Fill materials shall be placed in lifts not
exceeding 100 mm (4 in) in loose depth for hand-operated
compaction. Other lift thicknesses may be approved by the
appropriate Saudi Aramco Inspection Representative based on
a field test section using the intended compaction equipment.
6.3.2.3 Fill and backfill adjacent to structures such as retaining walls,
pits, and basements shall not be compacted with heavy
equipment, but shall be compacted with hand-operated
equipment to a distance of 1.2 meters (4 feet) or greater beyond
the sides of the structures. Every effort shall be made to place
backfill materials symmetrically and in uniform layers to
prevent unnecessary eccentric loading on a structure or
foundation.
6.3.2.4 Bedding and backfill for pipeline and utility trenches shall
conform to SAES-L-450, SAES-L-460, or SAES-S-070 as
appropriate.