Auger cast piles have become popular selections in many parts of the country where deep foundations are ordered. This notoriety is in part due to their relative price, fast installation time and utility over a broad range of soil temperaments when contrasted with other separate deep foundation options.
How the Greater Chicago Area Uses Auger Cast Piles
Auger cast piles are normally 12-24 inches across, but 36-inch diameters have been successfully adopted. Grout strengths typically fluctuate from 3,000-5,000 psi and restrain up to 12 cement sacks per cubic yard.
As with shafts drilled conventionally, auger cast piles can hold resistance from end bearing and side friction. Permissible vertical axial load limits usually cover loads from roughly 40-150 tons, in accordance with the soil conditions and pile size.
How They are Made
Auger cast piles are built with a flight hollow stem continuous auger powered using a drill motor. The drill motor and auger are typically held in the air by a crane.
Installation of the piles involves drilling the auger to a designated depth or until bearing is attained. Grout then gets pumped with pressure through the auger flight’s hollow stem and down a hole near the bottom. To prevent the hole from plugging up from drill spoils, the base of the auger gets a sacrificial plug inserted prior to drilling and is cleared out as the grout pumping starts.
While the grout’s being pumped, the auger is removed as it’s slowly spinning in order to leave a perpetual grout column. It’s best to leave around 5-15 feet of grout head over the foot of the auger as the auger’s being taken out—this way the grout uses a displacing effect and forces the extra drill spoils to the top of the hole where they’re eliminated from the auger’s flights by workers. The spoils are generally extracted from the auger cast pile’s area while they’re piling up, but an auger cast pile installation is still quite a messy process.
When to Consider Auger Cast Piles in the Greater Chicago Area
These piles are best suited for sites with soft or medium soil density contingencies. Such piles might not be fit to be installed where notable levels of embedment are required in dense rock or soil.
If you’ve been thinking about an auger cast pile installation for your commercial property near Chicago or Milwaukee, M3 Construction Solutions is here to help with your construction consultation and management solutions! Give us a call today at 815-363-8493 or fill out our contact form online for more info.