Most of the articles appearing in Helical Pile World tout the reasons why specifying professionals, contractors, and/or other influencers choose helicals. It is no secret that site conditions usually drive the decision to use helical technology versus another pile/anchoring system. Often, the elimination or the mitigation of site issues, to some extent, will also have a positive effect on cost containment on a given project. Dealing with site conditions costs time and money. However, this is less likely to be the case on new construction projects where job boogeymen, such as access and mobilization, are not at issue. This was the case on two jobs in Philadelphia – one on Dauphin Street and one on Pechin Street – which had wide-open sites where other deep foundation systems could have been utilized. With different soil dynamics, in both instances, the decision was to use helicals, but different helical products. The commonality: both piles got the job done and saved the owners money. The following two case studies illustrate how choosing the “right” helical pile can make helical technology the correct choice even over competing piling systems on straight-forward new construction projects.
Pechin Street, Philadelphia, PA
Back when coal was king, this underdeveloped neighborhood on Pechin Street in Philadelphia, PA was a dumping ground for coal ash. There was concern for the foundation piles with WOH corrosive soils. Joe Mulvihill at Ambric Technology was one of the earliest adapters to helical technology in our territory some 25 years ago and has kept up on product improvements and innovations over the years. He had specified the Grouted Helical Micropile in the past and, after a consultation with long time, veteran installer, Steve Vaspoli, recognized that this was the right pile for these conditions. The 6″ grout column surrounding the helical extensions would protect the steel from the corrosive ash fill. A bonus was the cost savings. This product pulls down a grout column around the extensions and is end-bearing on the helical plates, while picking up a friction component from the rough, uneven surface of the grout. Grout is less expensive than steel, providing a higher capacity pile at a much lower cost per foot. With 207 piles at 40 feet, the savings really added up.
Here is the link to the Pechin Street Case History.
This combo pile also deals with any buckling or lateral concerns often encountered in soils in urban environments like Pechin street. The grout column can also be sleeved with steel or PVC and be used in water or above grade, but at a sacrifice to the friction component. This bulletin “When in Doubt, Grout,” provides the details on how it works.
When In Doubt, Grout! Encasing Helical Piles In Grout – Danbro Distributors
More case studies on the GHM can be found here: Grouted Helical Micropiles Case Histories
Dauphin Street, Philadelphia, PA
Dauphin Street was the site of a 13-unit housing project in Philadelphia, PA. A deep foundation was required due to unstable soils and, with 101 piles advancing to 40’, the owner, Olympic Holdings, was looking for the most cost-effective solution. In this instance, our supplier, IDEAL Foundation Products, was the difference maker. No other manufacturer offers as many product options as IDEAL and it was the IDEAL advantage which carried the day for Vaspoli Builders, who was awarded the contract. As it turns out, IDEAL produces 3.5″ pipe piles with both a .300 and a .216 wall. The .216 wall pile provided enough torque and achieved the ultimate capacity at a lower cost than the .300 wall pile most manufacturers offer. With 101 piles on this site, the cost savings with the IDEAL product added up and won our contractor the bid.
Here is the link to the Dauphin Street Case History.
Two relatively straight-forward new construction projects that our contractor was able to win by bidding both jobs with competitive pricing due to the ability to provide the right helical solution at the best price.
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