This post is the first in a series of mythbusting queries about screw piles. We hear incorrect assumptions, statements and perceptions about screw piles a lot. The mythbusting series of posts will hopefully dispel some of those myths as false accusations.
For many years people in the construction industry have viewed screw piles as petite little piles that only go under residential or light commercial structures. 10 years ago I may have been inclined to agree with that sentiment, but a lot has happened in that time to the point where we have just completed a tension load test on a screw pile to 3250kN; that’s 325 tonnes.
So what has had to change to achieve huge capacity improvements? The answer is simpler than you might think; nothing really. Our design philosophies haven’t changed, we have merely up-sized each component in the system. Larger excavators driving larger power-heads, driving larger diameter and thicker walled pipe driving larger diameter helices into denser ground. The sum of all of those equates to pile capacities in excess of 4000kN in compression and 3250kN in tension.
Whilst Piletech are not in the business to make and break records, we expect that this will be a world record for tension capacity of a screw pile. Perhaps if anyone out there has information to the contrary they can let us know. We would like some further motivation to test to greater heights.