By Gary L. Seider
Pipe shaft helical piles have the ability to provide a superior foundation solution during disaster recovery and resistance when compared to other deep foundation options. Preliminary results show that helical piles offer improved seismic resistance due to their slenderness, higher dampening ratios, ductility and resistance to uplift.
Another reason helical piles are preferable during disaster relief efforts is the speed with which they're installed and attached to existing structures. On average, a crew can install as many as 25 to 30 helical piles in a single day.
Compared to other foundation alternatives, helical piles can also be more easily installed under a house that’s raised to meet flood requirements. During the Hurricane Sandy rebuild, helical piles were essential for remediation of homes needing to be raised to accommodate FEMA flood zone standards.
Contractors should consider helical piles when evaluating resistance methods that make the most sense for their respective project or structure. Also, if a building is constructed with the appropriate resistance methods, in the event of a natural disaster, the recovery efforts should be decreased.
Why Piles Can Prop Up Your Foundation Issues
Helical piles help contractors address deep foundation needs efficiently, preparing buildings for recovery and resistance from current and future natural disasters. Advantages of helical piles include:
- A cut in costs – Current research points to the very real possibility that helical piles produce higher dampening rates, reduced seismic design categories, and less seismic reinforcement. Verifying this data could be a financial benefit to pile users. Compared to other deep foundations, such as concrete drilled shafts, owners who use helical piles in areas that are vulnerable to natural disaster could receive a better solution with less out-of-pocket expense.
- More opportunities to retrofit – Helical piles require smaller equipment to screw the piles instead of drive them, which makes it easier to retrofit them to existing structures. Crews can install the piles easily even when site access is limited or the spot rests in a low-overhead area.
- A deeper structural support – Because helical piles insert independently, they don't rely on the weight of the structure to push them down farther. Instead, each pile screws deeper into the ground and can transfer a greater amount of weight into the more entrenched load-bearing strata. This makes them especially beneficial in soft ground, expansive soils, and other less sturdy grounds.
Pending research results, another cost-saving benefit to using helical piles may be creating deep foundations in lieu of concrete drilled shafts. If the data proves the theory, helical piles will be the solution of choice for structures that need to be prepared to combat the effects of unforeseen weather occurrences and natural disasters.
Gary L. Seider, P.E., is engineering manager of CHANCE® Civil and Utility Helical Products. Hubbell Power Systems Inc. manufactures a wide array of transmission, distribution, substation, OEM, and telecommunication products used by utilities.
With four U.S. patents and more than 40 years of industry experience, Seider oversees the company’s civil construction and utility application/project engineering staff. His team assists owners, engineers, and contractors with technical assistance, guidance, and recommendations for the proper use of CHANCE Helical Anchors and piles and Atlas Resistance® products.