A Summary of Densification Methods for Building Foundations
Deep Foundation Deposits
Typical Equipment and Procedures for Compaction
(A) Surface compaction by equipment
and procedures shown @ left is feasible
ASTM D 1557
only if material is at proper water
(B) Densification of soils is controlled by
tamper ( c )
ASTM D 1557
ASTM D 1557.
(B) Wet side
means of vertical drains.
at which one
Field control exercised by observation of
pore pressures and surface settlements.
of action of
(and not result
in voids or
Note: The above requirements will be adequate in relation to most construction. In special cases where tolerable settlements are unusually small, it may be necessary to employ additional
compaction equivalent to 95-100% of CE55 compaction effort. A coverage consists of one application of the wheel of a rubber tired roller of the treads of a crawler type tractor over each
point in the area being compacted. For a sharpefoot roller drum over the area being compacted.
a. Rubber tired rollers having a wheel load between 18,000 and 25,000 lbs. and a tire pressure between 80 and 100 psi.
b. Crawler type tractors weighing not less than 20,000 lbs and exerting a foot pressure not less than 6 psi.
c. Power hand tamper weighing more than 100 lbs: pneumatic or operated by gasoline engine.
d. Sharpfoot rollers having a foot pressure between 250 and 500 psi and tamping 7-10 tamp lengths with a face area between 7 and 16 sq. inches.