Commercial Foundation Repair in NJ, including Paterson, Tom's River & Jersey City.

Commercial Helical Anchors / Tiebacks

Helical Anchors (also referred to as tiebacks) provide lateral stability to foundation walls and retaining walls with unbalanced earth pressures. Helical anchors can be installed with hand-held equipment, mini-excavators, skid steers, backhoes, track hoes, or crane-supported rigs so the anchors can be installed in almost any application. This versatility, along with the ability to immediately load and test the anchors, make helicals a convenient and economical solution for a wide variety of projects.

helical tiebacks in New JerseyADVANTAGES

  • Predictable capacity
  • Helix blade configuration selected to achieve design embedment and capacity
  • All-weather installation
  • Can be installed in areas of limited or tight access
  • Installation does not generate spoils
  • Clean installation with no messy grout
  • Load tests can be performed immediately following installation
  • Available with optional hot-dip galvanizing for added corrosion protection

Design Considerations

Helical anchors are a factory-manufactured steel foundation system consisting of a central shaft with one or more helix-shaped bearing plates, commonly referred to as blades, welded to the lead section. Extension shafts, with or without additional helix plates, are used to extend the anchor into competent load-bearing soils. Helical anchors are advanced ("screwed") into the ground with the application of torque.

The terms helical piles, screw piles, helical piers, helical anchors, helix piers, and helix anchors are often used interchangeably by specifiers. However, the term "pier" more often refers to a helical foundation system loaded in axial compression, while the term "anchor" more often refers to a helical foundation system loaded in axial tension.

Determination of Capacity

The ultimate capacity of a helical anchor may be calculated using the traditional bearing capacity equation:

Qu = ∑ [Ah (cNc + qNq)]

Where:
Qu = Ultimate Anchor Capacity (lb)
Ah = Area of Individual Helix Plate (ft2)
c = Effective Soil Cohesion (lb/ft2)
Nc = Dimensionless Bearing Capacity Factor = 9
q = Effective Vertical Overburden Pressure (lb/ft2)
Nq = Dimensionless Bearing Capacity Factor

Total stress parameters should be used for short-term and transient load applications and effective stress parameters should be used for long-term, permanent load applications. A factor of safety of 2 is typically used to determine the allowable soil bearing capacity, especially if torque is monitored during the helical anchor installation.

Helical Anchor Tech

Like other deep foundation alternatives, there are many factors to be considered in designing a helical anchor foundation. Supportworks recommends that helical anchor design be completed by an experienced geotechnical engineer or other qualified professional.

Another well-documented and accepted method for estimating helical anchor capacity is by correlation to installation torque. In simple terms, the torsional resistance generated during helical anchor installation is a measure of soil shear strength and can be related to the bearing capacity of the anchor.

Qu = KT

Where:
Qu = Ultimate anchor Capacity (lb)
K = Capacity to Torque Ratio (ft-1)
T = Installation Torque (ft-lb)

The capacity to torque ratio is not a constant and varies with soil conditions and the size of the anchor shaft. Load testing using the proposed helical anchor and helix blade configuration is the best way to determine project-specific K-values. However, ICC-ES AC358 provides default K-values for varying anchor shaft sizes, which may be used conservatively for most soil conditions. The default value for the Model 150 Helical Anchor System (1.50" square shaft) is K = 10 ft-1.

-- View Our Helical Anchors and Tiebacks Product Specifications document --

Anchor Capacity

The cross-section of a square shaft is very compact which can allow the anchor to penetrate more easily through the soil. This compact shape also reduces the stiffness of the cross section and introduces more potential for buckling. These two factors make square shaft helical anchors better suited for tension loads. Supportworks, Inc. therefore recommends their use mainly for these types of applications. Square shaft helical anchors (piles) used in compression should be evaluated on a case by case basis by the project engineer.

Mechanical Axial Capacity (see note):

  • Allowable Tension = 26.5 kips*

* The mechanical tensile capacity of the Model 150 Helical Anchor System is limited by the allowable stress levels dictated by AISC for a high strength bolt in double shear. The allowable tensile capacity of the shaft is actually much higher than this Allowable Tension value.

Torque Limited Axial Design Capacities based on Ultimate Torsional
Resistance of Anchor Shaft = 6,340 ft-lbs**:

  • Ultimate Soil Capacity = 63.4 kips** (with K = 10 ft-1, see note)
  • Allowable Soil Capacity = 31.7 kips (FOS = 2, Allowable System Capacity therefore governed by mechanical capacity = 26.5 kips*)

** This Ultimate Torsional Resistance and its corresponding Torque Limited Capacities are based on laboratory test results from an IAS accredited facility and may only be approached in idealized conditions. Plastic torsional deformations can begin in the anchor shaft near 4,600 ft-lbs. This value may be reached and exceeded in the field by maintaining alignment between the anchor and the drive head, limiting impact forces and torque reversal, and reducing the tendency to "crowd" (push down on) the anchor. Installation through soils with obstructions or high variability may result in impact loading on the anchor. In these cases, achieving high torque values becomes more difficult and a further reduction in the Design Torque Limit may be appropriate.

Note

K = 10 ft-1 is a default value as published in ICC-ES AC358 which can, in many cases, be considered conservative. Higher capacities can often be achieved with site-specific load testing. Allowable capacities based on site testing shall not exceed the Mechanical Axial Capacity.

-- View Our Helical Anchors and Tiebacks Product Specifications document --

Model 150 Helical Anchor System

  • Outer Dimensions = 1.50" x 1.50"
  • Anchor Shaft Yield Strength = 90 ksi (min.)
  • Coupling Hardware: ¾" Grade 8 Bolt with Nut
  • Available Helix Blade Diameters = 6", 8", 10", 12" and 14"
  • Helix Blade Thickness = 0.375"
  • Termination Hardware: 1" Threaded Rod, Tensile Strength = 120 ksi (min.)

-- View Our Helical Anchors and Tiebacks Product Specifications document --

Model 175 Helical Anchor System

  • Outer Dimensions = 1.75" Round Corner Square Bar
  • Anchor Shaft Yield Strength = 90 ksi (min.)
  • Coupling Hardware: (2) ¾" Grade 8 Bolt with Nut
  • Available Helix Blade Diameters = 6", 8", 10", 12" and 14"
  • Helix Blade Thickness = 0.375"
  • Termination Hardware: 1" Threaded Rod, Tensile Strength = 120 ksi (min.)

-- View Our Helical Anchors and Tiebacks Product Specifications document --

Helix Blade Geometry

Helix Blade Geometry

Supportworks' helical anchors feature blades manufactured with a true helix shape conforming to the geometry criteria of ICC-ES AC358. The leading and trailing edges of true helix blades are within one-quarter inch of parallel to each other and any radial measurement across the blade is perpendicular to the anchor shaft. A true helix shape along with proper alignment and spacing of the blades is critical to minimize soil disturbance during installation.

Conversely, blades that are not a true helix shape are often formed to a 'duckbill' appearance. These plates create a great deal of soil disturbance and do not conform to the helix geometry requirements of ICC-ES AC358 since their torque to capacity relationships are not well documented.

Looking for a price? Get a no cost, no obligation free estimate.

Serving NJ including the Greater Paterson area
Our New Jersey Service Area
Cities in Bergen County, NJ
Allendale
Alpine
Bergenfield
Bogota
Carlstadt
Cliffside Park
Closter
Cresskill
Demarest
Dumont
East Rutherford
Elmwood Park
Emerson
Englewood
Englewood Cliffs
Fair Lawn
Fairview
Fort Lee
Franklin Lakes
Garfield
Glen Rock
Hackensack
Harrington Park
Hasbrouck Heights
Haworth
Hillsdale
Ho Ho Kus
Leonia
Little Ferry
Lodi
Lyndhurst
Mahwah
Maywood
Midland Park
Montvale
Moonachie
New Milford
North Arlington
Northvale
Norwood
Oakland
Oradell
Palisades Park
Paramus
Park Ridge
Ramsey
Ridgefield
Ridgefield Park
Ridgewood
River Edge
Rochelle Park
Rutherford
Saddle Brook
Saddle River
South Hackensack
Teaneck
Tenafly
Teterboro
Township Of Washington
Waldwick
Wallington
Westwood
Wood Ridge
Woodcliff Lake
Wyckoff

Cities in Burlington County, NJ
Beverly
Birmingham
Bordentown
Browns Mills
Burlington
Chatsworth
Chesterfield
Columbus
Cookstown
Delanco
Delran
Florence
Hainesport
Jobstown
Joint Base Mdl
Juliustown
Lumberton
Maple Shade
Moorestown
Mount Holly
Mount Laurel
New Lisbon
Palmyra
Pemberton
Rancocas
Riverside
Riverton
Roebling
Shamong
Southampton
Tabernacle
Vincentown
Willingboro
Wrightstown

Cities in Camden County, NJ
Pennsauken

Cities in Essex County, NJ
Belleville
Bloomfield
Caldwell
Cedar Grove
East Orange
Essex Fells
Fairfield
Glen Ridge
Irvington
Livingston
Maplewood
Millburn
Montclair
Newark
Nutley
Orange
Roseland
Short Hills
South Orange
Verona
West Orange

Cities in Hudson County, NJ
Bayonne
Harrison
Hoboken
Jersey City
Kearny
North Bergen
Secaucus
Union City
Weehawken
West New York

Cities in Hunterdon County, NJ
Annandale
Asbury
Bloomsbury
Califon
Clinton
Flemington
Frenchtown
Glen Gardner
Hampton
High Bridge
Lambertville
Lebanon
Milford
Oldwick
Pittstown
Pottersville
Ringoes
Stockton
Three Bridges
Whitehouse Station

Cities in Mercer County, NJ
Hightstown
Hopewell
Lawrence Township
Pennington
Princeton
Princeton Junction
Robbinsville
Titusville
Trenton
Windsor

Cities in Middlesex County, NJ
Avenel
Carteret
Colonia
Cranbury
Dayton
Dunellen
East Brunswick
Edison
Fords
Helmetta
Highland Park
Iselin
Keasbey
Kendall Park
Metuchen
Middlesex
Milltown
Monmouth Junction
Monroe Township
New Brunswick
North Brunswick
Old Bridge
Parlin
Perth Amboy
Piscataway
Plainsboro
Port Reading
Sayreville
Sewaren
South Amboy
South Plainfield
South River
Spotswood
Woodbridge

Cities in Monmouth County, NJ
Allenhurst
Allentown
Allenwood
Asbury Park
Atlantic Highlands
Avon By The Sea
Belford
Belmar
Bradley Beach
Brielle
Cliffwood
Colts Neck
Cream Ridge
Deal
Eatontown
Englishtown
Fair Haven
Farmingdale
Fort Monmouth
Freehold
Hazlet
Highlands
Holmdel
Howell
Keansburg
Keyport
Leonardo
Lincroft
Little Silver
Long Branch
Manasquan
Marlboro
Matawan
Middletown
Millstone Township
Monmouth Beach
Morganville
Neptune
Oakhurst
Ocean Grove
Oceanport
Port Monmouth
Red Bank
Roosevelt
Rumson
Sea Girt
Shrewsbury
Spring Lake
West Long Branch

Cities in Morris County, NJ
Boonton
Brookside
Budd Lake
Butler
Cedar Knolls
Chatham
Chester
Denville
Dover
East Hanover
Flanders
Florham Park
Gillette
Green Village
Hibernia
Kenvil
Lake Hiawatha
Lake Hopatcong
Landing
Ledgewood
Lincoln Park
Long Valley
Madison
Mendham
Millington
Mine Hill
Montville
Morris Plains
Morristown
Mount Arlington
Mount Freedom
Mount Tabor
Mountain Lakes
Netcong
New Vernon
Parsippany
Pequannock
Pine Brook
Pompton Plains
Randolph
Riverdale
Rockaway
Schooleys Mountain
Stirling
Succasunna
Towaco
Wharton
Whippany

Cities in Ocean County, NJ
Barnegat
Barnegat Light
Bayville
Beach Haven
Beachwood
Brick
Forked River
Island Heights
Jackson
Lakehurst
Lakewood
Lanoka Harbor
Lavallette
Little Egg Harbor Twp
Manahawkin
Manchester Township
Mantoloking
New Egypt
Ocean Gate
Pine Beach
Point Pleasant Beach
Seaside Heights
Seaside Park
Toms River
Tuckerton
Waretown
West Creek

Cities in Passaic County, NJ
Bloomingdale
Clifton
Haledon
Haskell
Hawthorne
Hewitt
Little Falls
Newfoundland
Oak Ridge
Passaic
Paterson
Pompton Lakes
Ringwood
Totowa
Wanaque
Wayne
West Milford

Cities in Somerset County, NJ
Basking Ridge
Bedminster
Belle Mead
Bernardsville
Bound Brook
Bridgewater
Far Hills
Flagtown
Franklin Park
Gladstone
Hillsborough
Kingston
Lyons
Manville
Martinsville
Neshanic Station
Peapack
Raritan
Rocky Hill
Skillman
Somerset
Somerville
South Bound Brook
Warren
Watchung
Zarephath

Cities in Sussex County, NJ
Andover
Augusta
Branchville
Franklin
Glenwood
Hamburg
Highland Lakes
Hopatcong
Lafayette
Layton
Montague
Newton
Ogdensburg
Sparta
Stanhope
Stockholm
Sussex
Vernon

Cities in Union County, NJ
Berkeley Heights
Clark
Cranford
Elizabeth
Elizabethport
Fanwood
Garwood
Hillside
Kenilworth
Linden
Mountainside
New Providence
Plainfield
Rahway
Roselle
Roselle Park
Scotch Plains
Springfield
Summit
Union
Vauxhall
Westfield

Cities in Warren County, NJ
Allamuchy
Belvidere
Blairstown
Columbia
Great Meadows
Hackettstown
Johnsonburg
Oxford
Phillipsburg
Port Murray
Stewartsville
Vienna
Washington

Cities in Rockland County, NY
Bear Mountain
Blauvelt
Congers
Garnerville
Grandview On Hudson
Haverstraw
Hillburn
Monsey
Nanuet
New City
Nyack
Orangeburg
Palisades
Pearl River
Piermont
Pomona
Sloatsburg
Sparkill
Spring Valley
Stony Point
Suffern
Tallman
Tappan
Thiells
Tomkins Cove
Valley Cottage
West Haverstraw
West Nyack

Cities in Berks County, PA
Bally
Barto
Bechtelsville
Hereford
New Berlinville

Cities in Bucks County, PA
Bensalem
Bristol
Buckingham
Carversville
Chalfont
Croydon
Doylestown
Dublin
Erwinna
Fairless Hills
Feasterville Trevose
Fountainville
Furlong
Jamison
Kintnersville
Langhorne
Levittown
Line Lexington
Milford Square
Morrisville
New Hope
Newtown
Ottsville
Perkasie
Pipersville
Point Pleasant
Quakertown
Richboro
Richlandtown
Riegelsville
Sellersville
Silverdale
Southampton
Springtown
Trumbauersville
Upper Black Eddy
Warminster
Warrington
Washington Crossing
Wycombe

Cities in Lehigh County, PA
Allentown
Center Valley
Coopersburg
Emmaus
Zionsville

Cities in Montgomery County, PA
Abington
Ambler
Bala Cynwyd
Blue Bell
Bridgeport
Bryn Athyn
Cheltenham
Collegeville
Colmar
Conshohocken
Dresher
East Greenville
Elkins Park
Flourtown
Fort Washington
Frederick
Gilbertsville
Gladwyne
Glenside
Green Lane
Gwynedd
Gwynedd Valley
Harleysville
Hatboro
Hatfield
Horsham
Huntingdon Valley
Jenkintown
King Of Prussia
Lafayette Hill
Lansdale
Merion Station
Montgomeryville
Narberth
Norristown
North Wales
Oaks
Oreland
Palm
Pennsburg
Perkiomenville
Plymouth Meeting
Pottstown
Red Hill
Royersford
Sassamansville
Schwenksville
Skippack
Souderton
Spring House
Telford
Willow Grove
Wyncote
Zieglerville

Cities in Northampton County, PA
Bethlehem
Easton
Hellertown

Our Locations: