This technique is used with deep soft soil
where it is impractical to find firm bedrock.
It eliminates the costs of drill spoil removal associated
with cast in situ piles, reduces on-site traffic and in cases
of ground contamination, eliminates the additional costs
resulting from treatment and disposal.
The compression of the surrounding soil beneath the pile tip
and along the pile shaft increases the mechanical characteristics
of the ground, improves the skin friction and end bearing capacity
of the pile.
It also enables monitoring of penetration rates, versus depth
by driving, to balance the bearing weight with the skin friction.
Skin friction can be further improved by utilising the grouted annulus installation method.