Auger Cast Piles
Posted in Uncategorized on February 28th, 2010 by admin – Be the first to commentAuger Cast Piles are installed by rotating a continuously flighted hollow shaft auger into the soil to a specified depth. High strength cement grout is pumped under pressure through the hollow shaft as the auger is slowly withdrawn. The resulting grout column hardens and forms an auger cast pile. Reinforcing, when required, can be installed while the cement grout is still fluid or (in the case of full length single reinforcing bars) through the hollow shaft of the auger prior to the withdrawal and grouting process.
Auger Cast Piles can be used:
* As friction piles – the superstructure load is transferred to the soil through friction between the pile surface and the soil;
* As an end-bearing pile – the superstructure load is transferred through the pile tip into a hard stratum of soil or rock;
* As an anchor pile – hydrostatic or other uplift forces are resisted though a full length tendon embedded in the grout column;
* As a vertical component of a continuous auger cast curtain wall in temporary or permanent shoring systems and below grade walls; and
* As a temporary or permanent diagonal tie-back in auger cast curtain walls, beam and lagging walls, and sheet pile walls.
Advantages
Less noise – augercast pile are a drilled and pumped pile, not a driven pile. This eliminates the hammer impact noise created by driving piles.
No objectionable vibration – The elimination of a pile-driving hammer allows the installation of auger cast piles adjacent to existing structures without the danger of settlement or damage to existing footings, walls, other structural components, or nearby equipment.
No casing required – During the installation of an auger cast pile, the earth filled auger maintains the shape of the pile hole during the drilling phase. The pressures produced by the grout pump during the withdrawal and grouting phase exceed the lateral pressures exerted by the soil, and while the gout is still fluid, the lateral pressures per foot of depth of the grout exceed those pressures per foot of depth of the soil.