“I have a skid steer post hole auger that should be able to get one of those in the ground.” A common statement by aspiring DIY screw pile installers. But… is this a good idea?
Common auger drives mounted to skid steers, back hoes or excavators and that are sold at retailers like Bobcat, New Holland, John Deere, Etc. are quite different from anchor drives which are only available by special order.
What is an auger drive? A high speed motor designed for earth augers to churn and disturb earth so that a hole can be easily bored.
What is an anchor drive? A high torque motor designed to slowly and continuously advance a screw pile causing as little disturbance to and shearing of the soil as possible.
Don’t you just need to simply get the pile in the ground?
Alan J. Lutenegger, John Erikson and Nocholas Williams, Departemtn of Civil and Environmental Engineering, University of Massachusetts in their report titled “Evaluating Installation Disturbance of Helical Anchors in Clay From Field Vane Tests” reported on a very interesting experiment which compared a screw pile installed professionally against a screw pile installed in a manner to mimic a DIY installation.
The results provided a very interesting insight with empirical data demonstrating that difference in capacity between professionally and poorly installed screw piles could be up to 2 times higher (see figure).
The report concluded that the quality of screw pile installation effects the disturbance of the soil and thus the performance of a screw pile.
For a professional screw pile installation backed by a performance guarantee contact Postech Screw Piles Manitoba and Kenora at 1-855-474-5464 or 204-793-0653 or visit www.screwpiling.ca.