Most often, ?600 bored cast in-situ pile is used for the foundation of abutments and piers.
There are 3 different drilling methods in cast-in-place concrete piles.
– Earth drill method
– Reverse circulation method
Considering the site conditions, availability of required equipment, speed and economy as well as the experiences in Sri Lanka, earth drill method will be employed for most of the project.
General procedure of Earth drill method of bored cast in-situ pile and its illustrations are –
- Installation of standpipe by a vibrator
- Excavation by earth drilling bucket
- Removal of slime by bucket (1st treatment)
- Installation of reinforcing steel bar cages
- Removal of slime by air-lift or suction method (2nd treatment)
- Placing concrete by tremie pipe