Serving NE, IA, KS, MO including the Greater Omaha area
Our Nebraska, Iowa, Kansas, 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 Humboldt County, IA
Bode
Bradgate
Dakota City
Hardy
Humboldt
Livermore
Ottosen
Rutland
Thor

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

Cities in Kossuth County, IA
Lu Verne

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
Gilmore City
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 Webster County, IA
Badger
Barnum
Callender
Clare
Dayton
Duncombe
Fort Dodge
Gowrie
Harcourt
Lehigh
Moorland
Otho
Vincent

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

Cities in Allen County, KS
Elsmore
Gas
Humboldt
Iola
La Harpe
Moran
Savonburg

Cities in Anderson County, KS
Centerville
Colony
Garnett
Greeley
Kincaid
Welda
Westphalia

Cities in Barber County, KS
Hardtner
Hazelton
Isabel
Kiowa
Lake City
Medicine Lodge
Sharon
Sun City

Cities in Barton County, KS
Albert
Claflin
Ellinwood
Great Bend
Hoisington
Olmitz
Pawnee Rock

Cities in Bourbon County, KS
Bronson
Fort Scott
Fulton
Garland
Mapleton
Redfield
Uniontown

Cities in Butler County, KS
Andover
Augusta
Beaumont
Benton
Cassoday
Douglass
El Dorado
Elbing
Latham
Leon
Potwin
Rosalia
Rose Hill
Towanda
Whitewater

Cities in Chase County, KS
Cedar Point
Cottonwood Falls
Elmdale
Matfield Green
Strong City

Cities in Chautauqua County, KS
Cedar Vale
Chautauqua
Niotaze
Peru
Sedan

Cities in Cherokee County, KS
Baxter Springs
Columbus
Crestline
Galena
Riverton
Scammon
Treece
Weir
West Mineral

Cities in Cheyenne County, KS
Bird City
Saint Francis

Cities in Clark County, KS
Ashland
Englewood
Minneola

Cities in Clay County, KS
Clay Center
Green
Longford
Morganville
Wakefield

Cities in Cloud County, KS
Aurora
Clyde
Concordia
Glasco
Jamestown
Miltonvale

Cities in Coffey County, KS
Burlington
Gridley
Le Roy
Lebo
Neosho Falls
Waverly

Cities in Comanche County, KS
Coldwater
Protection
Wilmore

Cities in Cowley County, KS
Arkansas City
Atlanta
Burden
Cambridge
Dexter
Maple City
Rock
Udall
Winfield

Cities in Crawford County, KS
Arcadia
Arma
Cherokee
Farlington
Franklin
Frontenac
Girard
Hepler
Mc Cune
Mulberry
Opolis
Pittsburg
Walnut

Cities in Decatur County, KS
Dresden
Jennings
Norcatur
Oberlin

Cities in Dickinson County, KS
Abilene
Chapman
Enterprise
Herington
Hope
Solomon
Talmage
Woodbine

Cities in Edwards County, KS
Belpre
Kinsley
Lewis
Offerle

Cities in Elk County, KS
Elk Falls
Grenola
Howard
Longton
Moline

Cities in Ellis County, KS
Catharine
Ellis
Hays
Pfeifer
Schoenchen
Victoria
Walker

Cities in Ellsworth County, KS
Ellsworth
Holyrood
Kanopolis
Lorraine
Wilson

Cities in Finney County, KS
Garden City
Holcomb
Pierceville

Cities in Ford County, KS
Bucklin
Dodge City
Ford
Fort Dodge
Spearville
Wright

Cities in Franklin County, KS
Lane
Ottawa
Pomona
Princeton
Rantoul
Richmond
Wellsville
Williamsburg

Cities in Geary County, KS
Fort Riley
Junction City
Milford

Cities in Gove County, KS
Gove
Grainfield
Grinnell
Park
Quinter

Cities in Graham County, KS
Bogue
Hill City
Morland
Penokee

Cities in Grant County, KS
Ulysses

Cities in Gray County, KS
Cimarron
Copeland
Ensign
Ingalls
Montezuma

Cities in Greeley County, KS
Tribune

Cities in Greenwood County, KS
Eureka
Fall River
Hamilton
Lamont
Madison
Neal
Piedmont
Severy
Virgil

Cities in Hamilton County, KS
Coolidge
Kendall
Syracuse

Cities in Harper County, KS
Anthony
Attica
Bluff City
Danville
Freeport
Harper
Waldron

Cities in Harvey County, KS
Burrton
Halstead
Hesston
Newton
North Newton
Sedgwick
Walton

Cities in Haskell County, KS
Satanta
Sublette

Cities in Hodgeman County, KS
Hanston
Jetmore

Cities in Jackson County, KS
Circleville
Delia
Denison
Holton
Hoyt
Mayetta
Soldier
Whiting

Cities in Jewell County, KS
Burr Oak
Esbon
Formoso
Jewell
Mankato
Randall
Webber

Cities in Kearny County, KS
Deerfield
Lakin

Cities in Kingman County, KS
Cunningham
Kingman
Murdock
Nashville
Norwich
Spivey
Zenda

Cities in Kiowa County, KS
Greensburg
Haviland
Mullinville

Cities in Labette County, KS
Altamont
Bartlett
Chetopa
Dennis
Edna
Mound Valley
Oswego
Parsons

Cities in Lane County, KS
Dighton
Healy

Cities in Lincoln County, KS
Barnard
Beverly
Lincoln
Sylvan Grove

Cities in Linn County, KS
Blue Mound
Mound City
Parker
Pleasanton
Prescott

Cities in Logan County, KS
Monument
Oakley
Winona

Cities in Lyon County, KS
Admire
Allen
Americus
Emporia
Hartford
Neosho Rapids
Olpe
Reading

Cities in Marion County, KS
Burns
Durham
Florence
Goessel
Hillsboro
Lehigh
Lincolnville
Lost Springs
Marion
Peabody
Ramona
Tampa

Cities in Marshall County, KS
Axtell
Beattie
Blue Rapids
Bremen
Frankfort
Home
Marysville
Oketo
Summerfield
Vermillion
Waterville

Cities in Mcpherson County, KS
Canton
Galva
Inman
Lindsborg
Marquette
Mcpherson
Moundridge
Roxbury
Windom

Cities in Meade County, KS
Fowler
Meade
Plains

Cities in Mitchell County, KS
Beloit
Cawker City
Glen Elder
Hunter
Simpson
Tipton

Cities in Montgomery County, KS
Caney
Cherryvale
Coffeyville
Dearing
Elk City
Havana
Independence
Liberty
Sycamore
Tyro

Cities in Morris County, KS
Burdick
Council Grove
Dwight
White City
Wilsey

Cities in Morton County, KS
Elkhart
Richfield
Rolla

Cities in Nemaha County, KS
Baileyville
Bern
Centralia
Corning
Goff
Oneida
Seneca
Wetmore

Cities in Neosho County, KS
Chanute
Erie
Galesburg
Saint Paul
Stark
Thayer

Cities in Ness County, KS
Arnold
Bazine
Beeler
Brownell
Ness City
Ransom
Utica

Cities in Norton County, KS
Almena
Clayton
Lenora
Norton

Cities in Osage County, KS
Burlingame
Carbondale
Lyndon
Melvern
Osage City
Overbrook
Quenemo
Scranton
Vassar

Cities in Osborne County, KS
Alton
Downs
Natoma
Osborne
Portis

Cities in Ottawa County, KS
Bennington
Delphos
Minneapolis
Tescott

Cities in Pawnee County, KS
Burdett
Garfield
Larned
Rozel

Cities in Phillips County, KS
Agra
Glade
Kirwin
Logan
Long Island
Phillipsburg
Prairie View

Cities in Pottawatomie County, KS
Belvue
Emmett
Havensville
Olsburg
Onaga
Saint George
Saint Marys
Wamego
Westmoreland

Cities in Pratt County, KS
Byers
Coats
Iuka
Pratt
Sawyer

Cities in Rawlins County, KS
Atwood
Herndon
Ludell
Mc Donald

Cities in Reno County, KS
Abbyville
Arlington
Buhler
Haven
Hutchinson
Nickerson
Partridge
Plevna
Pretty Prairie
South Hutchinson
Sylvia
Turon
Yoder

Cities in Republic County, KS
Agenda
Belleville
Courtland
Cuba
Munden
Narka
Norway
Republic
Scandia

Cities in Rice County, KS
Alden
Bushton
Chase
Geneseo
Little River
Lyons
Raymond
Sterling

Cities in Riley County, KS
Leonardville
Manhattan
Ogden
Randolph
Riley

Cities in Rooks County, KS
Damar
Palco
Plainville
Stockton
Woodston

Cities in Rush County, KS
Alexander
Bison
La Crosse
Liebenthal
Mc Cracken
Nekoma
Otis
Rush Center

Cities in Russell County, KS
Bunker Hill
Dorrance
Gorham
Lucas
Luray
Paradise
Russell
Waldo

Cities in Saline County, KS
Assaria
Brookville
Falun
Gypsum
New Cambria
Salina

Cities in Scott County, KS
Scott City

Cities in Sedgwick County, KS
Andale
Bentley
Cheney
Clearwater
Colwich
Derby
Garden Plain
Goddard
Greenwich
Haysville
Kechi
Maize
Mcconnell Afb
Mount Hope
Mulvane
Valley Center
Viola
Wichita

Cities in Seward County, KS
Kismet
Liberal

Cities in Shawnee County, KS
Auburn
Berryton
Rossville
Silver Lake
Tecumseh
Topeka
Wakarusa

Cities in Sheridan County, KS
Hoxie
Selden

Cities in Sherman County, KS
Edson
Goodland
Kanorado

Cities in Smith County, KS
Athol
Cedar
Gaylord
Kensington
Lebanon
Smith Center

Cities in Stafford County, KS
Hudson
Macksville
St John
Stafford

Cities in Stanton County, KS
Johnson
Manter

Cities in Stevens County, KS
Hugoton
Moscow

Cities in Sumner County, KS
Argonia
Belle Plaine
Caldwell
Conway Springs
Geuda Springs
Mayfield
Milan
Milton
Oxford
Peck
South Haven
Wellington

Cities in Thomas County, KS
Brewster
Colby
Gem
Levant
Rexford

Cities in Trego County, KS
Collyer
Ogallah
Wakeeney

Cities in Wabaunsee County, KS
Alma
Alta Vista
Eskridge
Harveyville
Maple Hill
Paxico

Cities in Wallace County, KS
Sharon Springs
Wallace
Weskan

Cities in Washington County, KS
Barnes
Clifton
Greenleaf
Haddam
Hanover
Hollenberg
Linn
Mahaska
Morrowville
Palmer
Washington

Cities in Wichita County, KS
Leoti
Marienthal

Cities in Wilson County, KS
Altoona
Benedict
Buffalo
Fredonia
Neodesha
New Albany

Cities in Woodson County, KS
Piqua
Toronto
Yates Center

Cities in Andrew County, MO
Fillmore

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
Testimonials

Push Pier System - Technical Information

Foundation Solutions in Nebraska, Iowa, Kansas, and Missouri

Push Pier Systems in Nebraska, Iowa, and Missouri

The FSI Push Pier System utilizes high-strength round steel tube and a load transfer bracket (retrofit foundation repair bracket) to stabilize and/or lift sinking or settling foundations.

The foundation bracket is secured against the existing footing and pier sections are driven hydraulically through the foundation bracket and into the soil below using the combined structural weight and any contributory soil load as resistance.

Pier sections are continuously driven until a suitable load-bearing stratum is encountered. At that point, the structure either begins to lift or the target pressure/load is achieved. The weight of the structure is then transferred from the unstable soil, to the foundation brackets, through the piers, and to firm load-bearing soil or bedrock.

Figure 1. Typical installation of FSI 288 Push Pier System in Nebraska
Figure 1. Typical installation of FSI 288

Push Pier System

The first pier section advanced into the ground includes a larger-diameter "friction reducing collar" welded to the lead end. This collar, being larger in diameter than the pier tube, effectively creates annular space around the pier as it is advanced through most clayey soils. In soft clay or clean sand and gravel, an annular space may only temporarily be created.

However, the larger diameter collar causes soil disturbance or remolding to occur, which also significantly reduces frictional resistance on the outside surface of the pier during driving.

The result is a driven pier that generates most of its capacity in end-bearing. Over time, the soils surrounding the pier relax back into the annular space and against the pier shaft. This provides an additional frictional component to the pier's capacity. Even though this frictional capacity may be significant, it is conservatively ignored in the determination of the pier's factor of safety against pier settlement.

The FSI Push Pier System develops a factor of safety against pier settlement by the pier installation methods used and the sequence with which multiple piers are driven and then re-loaded. Piers are first driven individually using the maximum weight of the structure and any contributory soil load.

After all of the piers are driven, the piers are re-loaded simultaneously, and the total reaction load is distributed over the multiple pier locations.

The average load on each pier during the load transfer operation is generally less than 75 percent of the load during pier installation/driving, for a factor of safety of at least 1.3. Typical factors of safety against pier settlement range from about 1.5 to 3.0, with higher values generally achieved for structures with greater rigidity.

Again, these factors of safety conservatively ignore any additional frictional component to the pier's capacity.

Design Considerations

The FSI Push Pier System was designed by licensed professional structural and geotechnical engineers (PE) on staff at FSI.

Currently, there are no standards that dictate how push pier systems are to be designed and tested. Therefore, many manufacturers of push pier systems simply fabricate a concept and then test according to their own self-approved methods. This often results in pier system capacities which are inappropriate and not representative of actual field applications.

FSI chose a different design approach. In June 2007, the International Code Council Evaluation Service, Inc. (ICC-ES) adopted AC358, Acceptance Criteria for Helical Foundation Systems and Devices. Sections of AC358 that discuss design and testing of pier shafts and side-load (retrofit foundation repair) brackets intuitively apply to push pier systems as well. FSI is confident that any future design and testing procedures adopted by the ICC-ES for push piers will closely follow the respective guidelines of AC358. Interested parties may review AC358 on-line at www.icc-es.org.

The FSI 288 Push Pier System was the very first in the industry to be designed and tested in accordance with an accepted standard, AC358.

Eccentric Loading

The pier tubes of a push pier system are not located directly under the structure's footing. Therefore, these systems are eccentrically loaded and in turn need to resist the bending forces generated by this loading condition. See Figure 2.

Eccentric Loading in Omaha

Figure 2. Eccentrically-loaded push pier system.

Overall dimensions of a pier cross section are typically less than four inches in most applications. These sections are therefore very sensitive to the bending moments introduced by this eccentricity, thereby reducing the capacity of the pier to carry axial load.

This sensitivity can be demonstrated with the following example. A given pier section with a 3.50-inch diameter, 0.30-inch wall thickness, and a yield strength of 36 ksi has a maximum allowable compressive capacity of 63.3 kips according to Allowable Stress Design. When a bending moment of 30 kip-in is applied to the same section, its allowable compressive capacity drops to 26.3 kips. This is a reduction of nearly 60 percent of the section's full axial capacity. What's more, this moment would equate to an equivalent eccentricity of only 1.14 inches, which is a seemingly small eccentricity and is well within the envelope of a typical pier cross section.

Fortunately, since the pier tubes are confined by the earth, these bending moments dissipate rather quickly into the surrounding soils within the first few feet. Softer soils will require these bending forces to dissipate over a greater length than stiffer soils. Foundation Supportworks has developed a unique, patent-pending method to address this issue (see next section).

Other methods exist to reinforce or partially reinforce this region of bending. However, with a critical eye and some understanding about how sensitive piers are to bending, one might question some capacities published by various manufacturers. It would appear that the effects of eccentric loading have been underestimated.

The FSI Push Pier System External Sleeve

The FSI 288 Push Pier System incorporates an external sleeve to resist the bending forces generated by the eccentric loading on the bracket, thereby preserving the axial compressive capacity of the pier. The external sleeve is hydraulically driven with and around the pier starter tube section to extend through and below the bracket. The effect of the sleeve essentially creates a bracket that is 48 inches long without any additional excavation. A 30-inch-long sleeve is available for use in limited headroom or crawl space applications.

The moment or bending force is localized within a relatively short distance below the bracket. Although the bending force is dissipated quickly by the pier bearing against the confining soil, it is significant and cannot be ignored. The depth or length of sleeve and pier over which the bending force dissipates is a function of the soil stiffness. The depth is greater in soft clay and loose sand, and less in stiff clay and dense sand. In soft or loose soils, a small portion of the bending force may be transferred to the pier below the sleeve, thereby reducing the pier's allowable axial compressive capacity.

Push Piers in Omaha
Figure 3. General arrangement.
Push Pier System.
Push Pier System in Omaha
Figure 4. Allowable capacities of FSI 288
Push Pier System.

Finite element software was used to analyze how the external sleeve and pier interact with soils of various properties. Bracket rotation is resisted not only by the rigidity of the pier system, but also by the passive pressure of the soil surrounding the external sleeve and the pier. Therefore, the capacity of the pier system is in part governed by the stiffness of the confining soils. Refer to Figure 4 for the allowable capacities of standard (48-inch sleeve) and crawl space (30-inch sleeve) 288 push pier systems in varying soil conditions.

Additional benefits of the external sleeve include:

  • Easy to install. The sleeve is driven at the same time as the starter tube. No additional steps.
  • Extra steel where it needs to be. Much more efficient than using thicker-walled pier tube sections over the entire pier length. The sleeve is a local solution to a local issue.
  • Sleeve is in place while driving pier tubes, which is when the system experiences maximum load.
  • No cumbersome internal reinforcement to install after driving. Internal reinforcement can be of inconsistent length and difficult to install properly. It may not be possible to install internal reinforcement if the pier yields or bends under load.
  • Sleeve penetration into the soil supports the bracket against kinking back and forth between each cylinder stroke.
  • Sleeve acts to guide pier sections into the ground at the recommended installation angle.
  • Sleeve length reduces friction loss between the pier bracket and pier tube, resulting in reduced hydraulic pressures during driving and lifting operations. This allows the hydraulic pressures to give a more accurate estimate of applied force.

The allowable capacities for the FSI 288 Push Pier System presented in Figure 4 consider a loss in steel thickness due to corrosion over a period of 50 years. The design period and corrosion loss rates are in accordance with ICC-ES AC358.

Bolting the Bracket to the Foundation

FSI does not require nor recommend bolting of the bracket to a concrete foundation with expansion or epoxy anchors. Experience has shown that bolting routinely causes concrete to crack and spall while drilling for and installing the anchors, or during the repeated loading/unloading procedure of driving piers. At best, bolting provides little benefit to the pier capacity and stability while introducing the potential to weaken the system by damaging the footing. Holes are included in the bracket to be used at the discretion of the installer or if a project engineer or building official requires that the piering system be positively attached to the structure.

Push Pier chart

Actually, the manner in which a push pier system is loaded and supported would tend to cause the bracket to push against the structure, not pull away from it. At the same time, however, while the bracket is pushing against the structure, it also tends to rotate toward the structure. If the pier system does not have adequate stiffness, then the tendency for excessive bracket rotation will be evidenced by the bearing plate being pried away from beneath the structure. This phenomenon does not mean that the overall pier system is translating away from the structure. Instead, it means the pier system needs to be much stiffer. The stiffness of the FSI 288 Push Pier System greatly reduces this rotational tendency and precludes the need to positively attach the bracket to the structure. When such an attachment is made due to preference or local requirements, FSI recommends the anchors be installed after completion of the piering operations.

Expansion or epoxy anchors to connect the bracket to the concrete foundation were not considered in the calculation of the allowable capacities noted in Figure 4. Anchors were also not used when the pier system was tested in accordance with AC358.

Corrosion Protection

The FSI Push Pier System was designed using the guidelines presented in ICC-ES AC358 for corrosion loss rates and design period (50 years). Corrosion loss rates are provided in AC358 for both bare steel and zinc-coated steel.

The pier tube used for the FSI Push Pier System is manufactured with a triple-layer, in-line galvanized coating. This coating process consists of: (1) a uniform hot-dip zinc galvanizing layer; (2) an intermediate conversion coating to inhibit the formation of white rust and enhance corrosion resistance; and (3) a clear organic top coating to further enhance appearance and durability. The inside of the pier tube also has a zinc-rich coating.

The pier system bracket, external sleeve, and pier cap are available standard as black steel or optional with a hot-dip zinc coating for galvanic protection. The bracket, sleeve, and pier cap analyzed for the determination of allowable capacity, as presented in Figure 4, were black steel. The hot-dip galvanization process is in accordance with ASTM A123, "Standard Specification for Zinc (Hot—Dip Galvanized) Coatings on Iron and Steel Products". The bracket and pier cap with steel plate thickness of at least 1/4-inch have an average zinc coating thickness of at least 3.9 mils (0.0039 inch) or 2.3 oz/ft2. The external sleeve with a wall thickness between 3/16-inch and 1/4-inch has an average zinc coating thickness of at least 3.0 mils (0.003 inch) or 1.7 oz/ft2.

The all-thread rod and heavy hex nuts come standard as zinc-plated in accordance with ASTM B633, "Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel".

Product Testing Procedures

As stated in an earlier section of this document, there are currently no standards that dictate how push pier systems are to be designed and tested. Therefore, many manufacturers of push pier systems simply fabricate a concept and then test according to their own self-approved methods. This often results in pier system capacities which are inappropriate and not representative of actual field applications. By compromising on test methods, manufacturers and installers are not aware of actual product limitations. Potential, unexpected issues are also not identified. Ultimately, compromised testing methods inhibit creativity and innovation in the industry. Simply designing a bracket to attain higher and higher test results by these inappropriate methods inhibits innovation for the design of pier systems that perform better in actual field conditions.

In June 2007, the International Code Council Evaluation Service, Inc. (ICC-ES) approved AC358, Acceptance Criteria for Helical Foundation Systems and Devices. Sections of AC358 that discuss design and testing of pier shafts and side-load (retrofit foundation repair) brackets intuitively apply to push pier systems as well. FSI is confident that any future design and testing procedures approved by the ICC-ES for push piers will closely follow the respective guidelines of AC358. Interested parties may review AC358 on-line at www.icc-es.org.

The FSI 288 Push Pier System was the very first in the industry to be designed and tested in accordance with an accepted standard, AC358.

Testing according to AC358 is much more demanding than many methods commonly practiced and considered acceptable across the industry. In many respects, results from tests completed in accordance with AC358 may be considered conservative. The criteria, as compared to other test procedures, more accurately determines failure loads. It also more appropriately identifies failure mechanisms of both the components of the pier system and the interface with the concrete structure. Refer to Figures 5, 6, and 7 for additional commentary regarding the differences in test procedures.

Push Piers for settled foundation in Omaha

Figure 5.

Stabilize foundation in Nebraska

Figure 5. Included in AC358 are specific criteria for the testing of side-load retrofit piering systems. The sketch is as it appears in the acceptance criteria illustrating an example of an appropriate laboratory test set up. The photo is of a FSI 288 Push Pier System being tested accordingly. As outlined in the test procedure, the exposed, unsupported length of pier from the bearing surface of the bracket to the point of fixity on the test frame is 60 inches. The bracket is mounted to a concrete block of known strength. The test sample is loaded until failure occurs at either the concrete interface or within the pier system's steel components. This test will not show failure loads in excess of those you would expect to see in actual application. Actually, one might consider the results of this test to be conservative since the component which contributes most to the systems strength, the external sleeve, is not supported by confining soils. Although the external sleeve makes a significant contribution to the strength of this test sample, the full benefit it provides is only realized when it's in the ground. This test method is very demanding and despite considering the results conservative, it is a very appropriate test method.

Fix foundation Iowa
Figure 6.
Unstable foundation Iowa Figure 7.

Figure 6. Additional testing of the FSI 288 Push Pier System illustrates how a manufacturer who does not wish to conform to AC358 may test their product. The test sample is made as short as possible to limit the exposed length of the pier. The bracket is mounted to a steel fixture which will prevent the system capacity from being limited by any potential concrete failure. The bracket is bolted to the fixture with high strength bolts which provide a far greater benefit than the concrete expansion anchors for which these holes are intended. The ultimate failure load for this test was 83,000 pounds. Since all of the pier system components are in place, this may be considered by some to be a fair test. If FSI did not have a long external sleeve as part of the system, the test might look different still."

Figure 7. A similar test arrangement as in Figure 6 is shown here. This time the external sleeve was trimmed down so it only extends slightly below the bracket. The test sample is again made as short as possible and the bracket is bolted to the steel fixture. Since this test sample is expected to exceed the results of the previous test, double cap plates are used to prevent the mode of failure from being bending of the cap plate. The ultimate failure load for this sample was 113,200 pounds. Manufacturers of systems without a similar reinforcing mechanism as the FSI External Sleeve may indeed test their products this way. Similarly, all of the pier system components are in place and, again, this may be considered by some to be a fair test. In addition to all the benefits enjoyed by the sample in the previous photo, this sample gets the added benefit of the lateral stiffness of the large hydraulic test apparatus. In contrast to the comments about the test sample in the Figure 6, having this specific arrangement confined by earth would prove to be a detriment and not a benefit since no soil could provide the lateral rigidity provided by the test apparatus. Having such a point of fixity certainly produces much higher test results.

Even non-technically minded individuals would agree that the FSI External Sleeve contributes a great deal to the stiffness and the strength of the pier system. They would be right. It actually increases the strength of the system by up to 40 percent. Yet when looking at the raw data of the tests just outlined, the sample without the sleeve tested 35 percent higher than the sample which included the sleeve. This is completely counterintuitive and illustrates perfectly the pitfalls of self-approved test methods. It inhibits progress and creativity since good designs may not test as well as poor ones. Tests conducted in such a manner have little basis in reality and make it impossible to make any direct comparisons between products.

One can see why manufacturers are not motivated to change their test procedures and why an appropriate standard for design and testing is so important. Foundation Supportworks has chosen to change the rules of the game. Our mission is to bring superior products to the marketplace, engineered to perform and tested in accordance with documented criteria. An accepted standard for push pier systems will bring a level playing field to the entire industry. In the meantime, there is AC358.

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