Serving NE, IA, MO including the Greater Omaha area
Our Nebraska, Iowa, and Missouri Service Area
Cities in Adams County, IA
Corning
Nodaway
Prescott

Cities in Audubon County, IA
Audubon
Brayton
Exira
Gray
Hamlin
Kimballton

Cities in Buena Vista County, IA
Albert City
Alta
Linn Grove
Marathon
Newell
Rembrandt
Sioux Rapids
Storm Lake
Truesdale

Cities in Calhoun County, IA
Farnhamville
Jolley
Knierim
Lake City
Lohrville
Lytton
Manson
Pomeroy
Rockwell City
Somers

Cities in Carroll County, IA
Arcadia
Breda
Carroll
Coon Rapids
Dedham
Glidden
Halbur
Lanesboro
Lidderdale
Manning
Templeton

Cities in Cass County, IA
Anita
Atlantic
Cumberland
Griswold
Lewis
Marne
Massena
Wiota

Cities in Cherokee County, IA
Aurelia
Cherokee
Cleghorn
Larrabee
Marcus
Meriden
Quimby
Washta

Cities in Clay County, IA
Dickens
Everly
Fostoria
Gillett Grove
Greenville
Peterson
Royal
Spencer
Webb

Cities in Crawford County, IA
Arion
Charter Oak
Deloit
Denison
Dow City
Kiron
Manilla
Ricketts
Schleswig
Vail
Westside

Cities in Dickinson County, IA
Arnolds Park
Lake Park
Milford
Okoboji
Spirit Lake
Superior
Terril

Cities in Emmet County, IA
Armstrong
Dolliver
Estherville
Ringsted
Wallingford

Cities in Fremont County, IA
Farragut
Hamburg
Imogene
Percival
Randolph
Riverton
Sidney
Tabor
Thurman

Cities in Harrison County, IA
Dunlap
Little Sioux
Logan
Magnolia
Missouri Valley
Modale
Mondamin
Persia
Pisgah
Woodbine

Cities in Ida County, IA
Arthur
Battle Creek
Galva
Holstein
Ida Grove

Cities in Lyon County, IA
Alvord
Doon
George
Inwood
Larchwood
Lester
Little Rock
Rock Rapids

Cities in Mills County, IA
Emerson
Glenwood
Hastings
Henderson
Malvern
Pacific Junction
Silver City

Cities in Monona County, IA
Blencoe
Castana
Mapleton
Moorhead
Onawa
Rodney
Soldier
Ute
Whiting

Cities in Montgomery County, IA
Elliott
Grant
Red Oak
Stanton
Villisca

Cities in Obrien County, IA
Archer
Calumet
Hartley
Paullina
Primghar
Sanborn
Sheldon
Sutherland

Cities in Osceola County, IA
Ashton
Harris
Melvin
Ocheyedan
Sibley

Cities in Page County, IA
Blanchard
Braddyville
Clarinda
Coin
College Springs
Essex
Northboro
Shambaugh
Shenandoah
Yorktown

Cities in Palo Alto County, IA
Ayrshire
Curlew
Cylinder
Emmetsburg
Graettinger
Mallard
Ruthven

Cities in Plymouth County, IA
Akron
Hinton
Kingsley
Le Mars
Merrill
Remsen
Westfield

Cities in Pocahontas County, IA
Fonda
Havelock
Laurens
Palmer
Plover
Pocahontas
Rolfe
Varina

Cities in Pottawattamie County, IA
Avoca
Carson
Carter Lake
Council Bluffs
Crescent
Hancock
Honey Creek
Macedonia
Mc Clelland
Minden
Neola
Oakland
Treynor
Underwood
Walnut

Cities in Sac County, IA
Auburn
Early
Lake View
Nemaha
Odebolt
Sac City
Schaller
Wall Lake

Cities in Shelby County, IA
Defiance
Earling
Elk Horn
Harlan
Irwin
Kirkman
Panama
Portsmouth
Shelby
Westphalia

Cities in Sioux County, IA
Alton
Boyden
Chatsworth
Granville
Hawarden
Hospers
Hull
Ireton
Maurice
Orange City
Rock Valley
Sioux Center

Cities in Taylor County, IA
Bedford
Blockton
Clearfield
Gravity
Lenox
New Market
Sharpsburg

Cities in Woodbury County, IA
Anthon
Bronson
Correctionville
Cushing
Danbury
Hornick
Lawton
Moville
Oto
Pierson
Salix
Sergeant Bluff
Sioux City
Sloan
Smithland

Cities in Atchison County, MO
Fairfax
Rock Port
Tarkio
Watson
Westboro

Cities in Holt County, MO
Craig
Forest City
Maitland
Mound City
Oregon

Cities in Nodaway County, MO
Barnard
Burlington Junction
Clearmont
Clyde
Conception
Conception Junction
Elmo
Graham
Guilford
Hopkins
Maryville
Parnell
Pickering
Ravenwood
Skidmore

Cities in Adams County, NE
Ayr
Hastings
Holstein
Juniata
Kenesaw
Roseland

Cities in Antelope County, NE
Brunswick
Clearwater
Elgin
Neligh
Oakdale
Orchard
Royal

Cities in Blaine County, NE
Brewster
Dunning
Purdum

Cities in Boone County, NE
Albion
Belgrade
Cedar Rapids
Petersburg
Primrose
Saint Edward

Cities in Boyd County, NE
Bristow
Butte
Lynch
Naper
Spencer

Cities in Brown County, NE
Ainsworth
Johnstown
Long Pine

Cities in Buffalo County, NE
Amherst
Elm Creek
Gibbon
Kearney
Miller
Odessa
Pleasanton
Ravenna
Riverdale
Shelton

Cities in Burt County, NE
Craig
Decatur
Lyons
Oakland
Tekamah

Cities in Butler County, NE
Abie
Bellwood
Brainard
Bruno
David City
Dwight
Linwood
Rising City
Surprise
Ulysses

Cities in Cass County, NE
Alvo
Avoca
Cedar Creek
Eagle
Elmwood
Greenwood
Louisville
Manley
Murdock
Murray
Nehawka
Plattsmouth
South Bend
Union
Weeping Water

Cities in Cedar County, NE
Belden
Coleridge
Fordyce
Hartington
Laurel
Magnet
Randolph
Saint Helena
Wynot

Cities in Clay County, NE
Clay Center
Deweese
Edgar
Fairfield
Glenvil
Harvard
Inland
Ong
Saronville
Sutton
Trumbull

Cities in Colfax County, NE
Clarkson
Howells
Leigh
Rogers
Schuyler

Cities in Cuming County, NE
Bancroft
Beemer
West Point
Wisner

Cities in Custer County, NE
Anselmo
Ansley
Arnold
Broken Bow
Callaway
Comstock
Mason City
Merna
Oconto
Sargent
Westerville

Cities in Dakota County, NE
Dakota City
Emerson
Homer
Hubbard
Jackson
South Sioux City

Cities in Dawson County, NE
Cozad
Eddyville
Farnam
Gothenburg
Lexington
Overton
Sumner
Willow Island

Cities in Dixon County, NE
Allen
Concord
Dixon
Maskell
Newcastle
Ponca
Wakefield
Waterbury

Cities in Dodge County, NE
Ames
Dodge
Fremont
Hooper
Nickerson
North Bend
Scribner
Snyder
Uehling
Winslow

Cities in Douglas County, NE
Bennington
Boys Town
Elkhorn
Omaha
Valley
Waterloo

Cities in Fillmore County, NE
Exeter
Fairmont
Geneva
Grafton
Milligan
Ohiowa
Shickley
Strang

Cities in Franklin County, NE
Bloomington
Campbell
Franklin
Hildreth
Naponee
Riverton
Upland

Cities in Frontier County, NE
Curtis
Eustis
Maywood
Moorefield
Stockville

Cities in Furnas County, NE
Arapahoe
Beaver City
Cambridge
Edison
Hendley
Holbrook
Oxford
Wilsonville

Cities in Gage County, NE
Adams
Barneston
Beatrice
Blue Springs
Clatonia
Cortland
Filley
Liberty
Odell
Pickrell
Virginia
Wymore

Cities in Garfield County, NE
Burwell

Cities in Gosper County, NE
Elwood
Smithfield

Cities in Greeley County, NE
Greeley
Scotia
Spalding
Wolbach

Cities in Hall County, NE
Alda
Cairo
Doniphan
Grand Island
Wood River

Cities in Hamilton County, NE
Aurora
Giltner
Hampton
Hordville
Marquette
Phillips

Cities in Harlan County, NE
Alma
Orleans
Ragan
Republican City
Stamford

Cities in Hayes County, NE
Hayes Center

Cities in Hitchcock County, NE
Culbertson
Palisade
Stratton
Trenton

Cities in Holt County, NE
Amelia
Atkinson
Chambers
Emmet
Ewing
Inman
Oneill
Page
Stuart

Cities in Howard County, NE
Boelus
Dannebrog
Elba
Farwell
Saint Libory
Saint Paul

Cities in Jefferson County, NE
Daykin
Diller
Endicott
Fairbury
Jansen
Plymouth
Steele City

Cities in Johnson County, NE
Cook
Crab Orchard
Elk Creek
Sterling
Tecumseh

Cities in Kearney County, NE
Axtell
Heartwell
Minden
Wilcox

Cities in Keya Paha County, NE
Mills
Newport
Springview

Cities in Knox County, NE
Bloomfield
Center
Creighton
Crofton
Niobrara
Verdigre
Wausa
Winnetoon

Cities in Lancaster County, NE
Bennet
Davey
Denton
Firth
Hallam
Hickman
Lincoln
Malcolm
Martell
Panama
Raymond
Roca
Sprague
Walton
Waverly

Cities in Lincoln County, NE
Brady
Dickens
Hershey
Maxwell
North Platte
Sutherland
Wallace
Wellfleet

Cities in Logan County, NE
Stapleton

Cities in Loup County, NE
Taylor

Cities in Madison County, NE
Battle Creek
Madison
Meadow Grove
Newman Grove
Norfolk
Tilden

Cities in Merrick County, NE
Archer
Central City
Chapman
Clarks
Palmer
Silver Creek

Cities in Nance County, NE
Fullerton
Genoa

Cities in Nemaha County, NE
Auburn
Brock
Brownville
Johnson
Julian
Nemaha
Peru

Cities in Nuckolls County, NE
Hardy
Lawrence
Nelson
Oak
Ruskin
Superior

Cities in Otoe County, NE
Burr
Douglas
Dunbar
Lorton
Nebraska City
Otoe
Palmyra
Syracuse
Talmage
Unadilla

Cities in Pawnee County, NE
Burchard
Du Bois
Lewiston
Pawnee City
Steinauer
Table Rock

Cities in Phelps County, NE
Atlanta
Bertrand
Funk
Holdrege
Loomis

Cities in Pierce County, NE
Hadar
Mclean
Osmond
Pierce
Plainview

Cities in Platte County, NE
Columbus
Creston
Duncan
Humphrey
Lindsay
Monroe
Platte Center

Cities in Polk County, NE
Osceola
Polk
Shelby
Stromsburg

Cities in Red Willow County, NE
Bartley
Danbury
Indianola
Lebanon
Mc Cook

Cities in Richardson County, NE
Dawson
Falls City
Humboldt
Rulo
Salem
Shubert
Stella
Verdon

Cities in Rock County, NE
Bassett

Cities in Saline County, NE
Crete
De Witt
Dorchester
Friend
Swanton
Tobias
Western
Wilber

Cities in Sarpy County, NE
Bellevue
Gretna
La Vista
Offutt Afb
Omaha
Papillion
Springfield
St Columbans

Cities in Saunders County, NE
Ashland
Cedar Bluffs
Ceresco
Colon
Ithaca
Malmo
Mead
Memphis
Morse Bluff
Prague
Valparaiso
Wahoo
Weston
Yutan

Cities in Seward County, NE
Beaver Crossing
Bee
Cordova
Garland
Goehner
Milford
Pleasant Dale
Seward
Staplehurst
Utica

Cities in Sherman County, NE
Ashton
Hazard
Litchfield
Loup City
Rockville

Cities in Stanton County, NE
Pilger
Stanton

Cities in Thayer County, NE
Alexandria
Belvidere
Bruning
Byron
Carleton
Chester
Davenport
Deshler
Gilead
Hebron
Hubbell
Reynolds

Cities in Thomas County, NE
Halsey
Seneca
Thedford

Cities in Thurston County, NE
Macy
Pender
Rosalie
Thurston
Walthill
Winnebago

Cities in Valley County, NE
Arcadia
Elyria
North Loup
Ord

Cities in Washington County, NE
Arlington
Blair
Fort Calhoun
Herman
Kennard
Washington

Cities in Wayne County, NE
Carroll
Hoskins
Wayne
Winside

Cities in Webster County, NE
Bladen
Blue Hill
Guide Rock
Inavale
Red Cloud

Cities in Wheeler County, NE
Bartlett
Ericson

Cities in York County, NE
Benedict
Bradshaw
Gresham
Henderson
Mc Cool Junction
Waco
York

Our Locations:

Thrasher Commercial
12330 Cary Circle
La Vista, NE 68128
1-402-685-2739

Helical Anchor System - Model 150 Technical Information

Foundation Solutions in Nebraska, Iowa, and Missouri

Helical anchors are designed such that most of the axial capacity of the anchor is generated through bearing of the helix blades against the soil. The helix blades are typically spaced three diameters apart along the anchor shaft to prevent one blade from contributing significant stress to the bearing soil of the adjacent blade. Significant stress influence is limited to a 'bulb' of soil within about two helix diameters from the bearing surface in the axial direction and one helix diameter from the center of the anchor shaft in the lateral direction. Each helix blade therefore acts independently in bearing along the anchor shaft.

Multiple anchors shall have a center to center spacing at the helix depth of at least four (4) times the diameter of the largest helix blade (ICC-ES AC358). The tops of the anchors may be closer at the ground surface but installed at a batter or angle away from each other in order to meet the spacing criteria at the helix depth. Helix blades shall have an embedment depth of at least twelve (12) diameters in the direction of loading (ICC-ES AC358).

Helical Tieback Diagram installed in Nebraska, Iowa, and Missouri

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. Foundation 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.

 

Side Wall Anchor Diagram installed in Nebraska, Iowa, and Missouri

 

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*)

Helical Tieback installed in Nebraska, Iowa, and Missouri

**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.

Technical Specifications

Coupling Detail Diagram

  • 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: Ø1" Threaded Rod
    • Tensile Strength = 120 ksi (min.)

Coupling Detail

The extensions for the Model 150 Helical Anchor System are manufactured with forged, upset ends that are drilled to create a socket and bolt coupling. Direct, sufficient contact of the anchor shaft is much more difficult to achieve within upset couplings than couplings for shafts with machine cut ends. The coupling bolt then acts in double shear for both tension and compression applications. Since FSI recommends that square shaft anchors be used mainly to resist tension loads, this level of precision is not justified.

Model 150 Helical Anchor System Applications

Anchors can be installed in places with limited access Helical Anchor Pull Test in Iowa

The Model 150 Helical Anchor System provides 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, trackhoes, or crane-supported rigs so the installation equipment can be sized for the project.

Model 150 Helical Anchor System Advantages

  • 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

Model 150 Helical Anchor System Applications

Foundation Supportworks recommends that all helical anchors be pre-tensioned following installation. Pre-tensioning to the design load minimizes deflection of the anchors and structure as the anchors are put into service. Anchors can also be "pull tested" or load tested to typically two (2) times the design load or more to identify the ultimate system capacity, better assess soil conditions and soil/anchor interaction, and validate design procedures.

 

Tension Assembly Tech Diagram

 

[Back to Technical Information overview]