Construction methods · Driven piles

SIP and pre-bored driven piles

A hole is augered slightly larger than the pile and filled with cement slurry; the precast pile is lowered and lightly driven or pressed into it. It gives a driven pile's simplicity without the noise and vibration, at the price of lower shaft friction and a wait for the slurry.

How bridges get built · Driven piles · SIP and pre-bored driven piles

Also called: soil-cement injected precast pile, pre-bored PHC, SIP method

How it is done

Auger the hole to near the bearing layer, injecting cement milk to stabilise it.
Lower the PHC pile, then drive the last 1-3 m into the bearing layer with a light hammer to seat it.
Cure the slurry; test a sample by PDA and static load.

Where it fits

Urban sites in Korea and Japan with noise and vibration limits; approach viaducts near houses; dense upper layers over a bearing layer.

Where it does not

Where full driven shaft friction is needed; loose sands where the hole collapses.

Plant, pace and money

PlantAuger rig, slurry plant, light hammer.

Productivity4-8 piles per shift.

CostUSD 120-220 per metre, above plain driving.

Risks and controls

What goes wrong

Poor slurry quality giving low friction; seating blows damaging the head.

Quality assurance

Slurry density and volume, seating blow counts, load tests.

Examples

The default urban pile in Korea; the game offers it for urban viaducts.