Caution over 250 tonne SWL Piles
Be cautious: some screw piling contractors are claiming to be installing single piles up to 250 tonne SWL capacity. There are very few piling rigs in Australia that could install a single screw pile greater than 1,000 kN limit state, which is towards the upper limit of our own current equipment.
Russell Heale Screw Piling has many years experience in the screw piling industry and our engineer has in excess of 1,000 static load test results. We conclude some projects have piles installed that have load capacity very much less than claimed. Unless these piles are end bearing on bedrock (which is very difficult, if not impossible to achieve with screw piles), and geotechnically capable of the concentrated load, we believe it is not possible to achieve such high loads.
Should you have concerns regarding screw piling we suggest that you consider specifying static load testing to be conducted on site to AS 2159-2009 Piling- Design and Installation parameters. The process should be monitored by a professional engineer who is experienced with load testing.
Alternatively, the engineers at P.J. Yttrup and Associates of Geelong, Victoria could review the proposed pile design. They are among the leading authority in Australia in screw pile design. Peter Yttrup has been on the AS2870 Residential Slabs and Footings and AS 2159 Piling Design and Installation committees for many years and is an associate professor of the University of Tasmania.
After all, if it sounds too good to be true, it usually is!