“A certified contractor is important but certified does not actually mean qualified” said John Pack, VP of Engineering at HELI-PILE on June 4th, 2019 at the DFI’s Helical Pile and Tieback Anchors conference in Cincinnati.
Engineered helical piles are not new to Manitoba, they have been used for decades and, until recently, their use was most popular in the utility sector and more specifically Hydro projects. Over the past 8 years the use of helical piles has grown beyond the utility sector and into the light capacity markets such as residential, light commercial and recreational. More recently, our helical piles are being engineered to support high capacity structures such as apartment buildings, communications towers, elevator shafts, grain towers, strip malls, large fabric structures, commercial signs, and more.
For selfish reasons, as passionate helical pile contractors, we really appreciate John Pack’s presentation. Our approach is conservative because we recognize we are only a foundation failure away from a tainted reputation. Manitobans could be led to believe helical piles are not a viable or reliable option in Manitoba gumbo – this is far from true. Manitoba has a lot of certified helical pile contractors but a lack of qualified helical pile contractors – this could prove problematic.
Helical pile contractors need to know their stuff and get outright nerdy about the engineering behind helical piles. I’m 8 years into helical piles as I write this article, I’ve delivered technical presentations on helical piles to rooms of engineers and been party to thousands of installations – I’m learning everyday. I haven’t learned everything there could possibly be to know about helical piles, there is still a lot I will learn, however, I do know that a 1 or 2 day course put on by a manufacturer is not enough to qualify a helical pile contractor as worthy to be on your project site when the stakes are high. Decks, docks or pergolas might not be so crucial but when the stakes increase, the qualifications of the contractor matter more and more.
Most of my learning has been outside of manufacturer certification processes. I’ve learned most from resources such as the Helical Pile Foundation Design Guide available from DFI, the Helical Piles – A Practical Guide to Design and Installation textbook by Howard A. Perko, the Canadian Foundation Engineering Manual, attending the Helical Pile – Tieback Anchors conference this past June, discussions with engineers on principles of limit state design as well as discussions with great and not so great helical pile contractors. Often my General Manager, Dale Plett B.Sc.Eng acts as my translator so I can best understand the factors which should be considered for an installation. The beauty of learning beyond a manufacturer’s certification process is that you get past their biases and you start to appreciate the qualified opinions of folks who really have very little vested interest in helical piles sales.
A helical pile contractor who can simply install a pile plumb with accuracy and relate torque to a chart provided by a manufacturer without all the extra knowledge required to put torque into context, is risky. Torque as a predictor of capacity is reliable but there are many factors which effect this relationship and therefore torque does not “dummy proof” a helical pile installation. There are times when a manufacturer’s basic guidelines will be just fine, but, from what I’ve seen the manufacturer specific engineering is typically aggressive when compared to the more universal guidelines outlined in the Helical Pile Foundation Design Guide by DFI or the textbook, Helical Piles – A Practical Guide to Design and Installation by Howard A. Perko. Unfortunately some manufacturer specific engineering is really aggressive and might claim loading 2, 3 or 4 times higher than where you might arrive adopting a universally accepted approach.
Not all manufacturers adopt their aggressive approach to bamboozle customers into believing they have the better pipe and bearing blade; some are just limited in the testing they’ve done. Some are simply expert manufacturers who can build a pile but who aren’t experts in helical pile engineering.
A qualified helical pile contractor will observe things such as: the quality of the materials and welding; all of the possible forces at play (sometimes there is a bending moment or lateral load overlooked by the design engineer), soils characteristics for the project site, how installation equipment could impact performance (is there enough crowd), when manufacturer guidelines are risky, the size and thickness of the helix or shaft diameter and it’s impact on torque, the proximity in which the piles are placed, etc. A qualified helical pile contractor will raise red flags and highlight any potential issues where a less qualified contractor will typically install the piles as quickly as possible and hit the road. You should also be able to receive engineer stamped close out letters from qualified contractors. The close out letters could be from a manufacturer’s in-house engineer but they are most credible when provided by a third party engineer.
VersaPile, Inc. will continue to learn and apply more conservative and universally adopted principles as we continue to build our reputation as world class qualified helical pile contractors.
By Stan Higgins, President of VersaPile, Inc., 204.793.0679 or email@example.com