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Foundation Supportworks Announces HelicastTM - a Grouted Helical Pile
by Bill Bonekemper
Foundation Supportworks®, Inc. www.onstableground.com. (FSI) is announcing the addition of the Helicast™ Grouted Helical Pile System to a helical pile lineup that already includes both hollow round shaft helical piles and solid square shaft helical anchors. FSI offers round shaft piles with outside diameters from 2.375 to 7.000 inches and high-strength square bar anchors in sizes of 1.50 and 1.75 inches. Larger pile and anchor sizes are available for custom order.
The most common solid square and hollow round shaft sizes can be advanced with smaller installation equipment, yet can achieve allowable torque-correlated capacities up to about 65 kips. However, when square shaft is used in compression applications, or when slender round shaft helical piles are advanced through loose, soft, or fluid soils, buckling analyses should be considered, which may result in either down-rating the pile capacity and requiring more piles, or upsizing to a larger shaft diameter that can support the design working loads. The Helicast™ Grouted Helical Pile System generates capacity as a combination of end-bearing and skin friction and may be considered to address a buckling concern or for its other potential benefits.
Helicast™ piles consist of standard solid square shaft lead and extension sections with soil displacement plates at each coupler location. The pile is advanced through a grout reservoir at the surface. The soil displacement plates push soil outward and away from the central shaft and allows specialty grout from the reservoir to flow by gravity into the void being created. The result is a helical pile with grout-encased extensions.
Helicast™ piles can be advanced with smaller equipment in limited access areas. Installation is vibration free and does not generate spoils.
The grout column surrounds the pile shaft and square bar couplers to create a pile that is more resistant to buckling.
The grout column offers additional corrosion protection in aggressive soil profiles.
A grouted helical pile may develop capacity in marginal soil conditions where a standard end-bearing helical pile may not. There is additional “frictional” capacity at the grout/soil interface.
Frictional piles typically deflect less than end-bearing piles for a given load.
Where favorable soil conditions exist, a Helicast™ pile may achieve allowable capacities exceeding 100 kips, which may then be considered as an economical alternative to large diameter helical shaft sizes or other deep foundation options.
FSI is ready to assist contractors with the marketing, design and installation of Helicast™ piles. Marketing brochures, model specifications, technical documents, installation guidelines and installation log templates are available. A Helicast™ design module has also been added to HelixPro®, FSI’s web-based helical pile design software.
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Omaha, NE 68128