Commercial Foundation Repair in MT and WY, including Bozeman, Belgrade & Jackson.
Commercial Push Pier Installation in Miles City

Push piers lift and stabilize commercial foundations to provide a permanent solution.

Commercial Push Pier Systems

The Foundation Supportworks Push Pier System utilizes high-strength round steel tubes 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.

The Foundation Supportworks 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. Since the average load on each pier during the load transfer operation is less than the load during pier installation/driving, a factor of safety against settlement is achieved. 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. These factors of safety conservatively ignore any additional long-term frictional component to the pier's capacity (see below for more information).

Foundation Supportworks Model 288 Pier System Specifications

  • Bracket: Weldment manufactured from 0.25", 0.375", and 0.50"-thick steel plate. Yield strength = 36 ksi (min.), tensile strength = 58 ksi (min.).
  • External Sleeve: 3.50" OD x 0.216" wall x 30" or 48" long with sleeve collar welded to one end. Yield strength = 50 ksi (min.), tensile strength = 62 ksi (min.).
  • Pier Starter Tube: 2.875" OD x 0.165" wall x 50" long, triple-coated in-line galvanized. Yield strength = 50 ksi (min.), tensile strength = 55 ksi (min.). 3.375" OD x 0.188" wall x 1" long friction reducing collar welded to one end.
  • Pier Tube: 2.875" OD x 0.165" wall x 36" long, triple-coated in-line galvanized. Yield strength = 50 ksi (min.), tensile strength = 55 ksi (min.). 2.50" OD x 0.180" wall x 6" long internal coupler at one end with 3" extending out of pier tube.
  • Pier Cap: 5.0" wide x 9.0" long x 1" thick plate with confining ring welded to one side. Yield strength = 50 ksi (min.), tensile strength = 65 ksi (min.).
  • All-Thread Rod: 0.75" diameter x 16" long, zinc plated, Grade B7, tensile strength = 125 ksi [min.].

-- View Our Push Pier System Product Specifications document --

Foundation Supportworks Model 288 Capacity Summary

Soil Strength Parameters(2)

Allowable System Capacity(1,2,3,4,5) (kips)

Allowable System Capacity(1,2,3,4,5) (kips)

Soil Type

Consistency/
Relative Density

SPT, N-Value

Cohesion (psf)

Friction Angle (degrees)

48" Ext. Sleeve

30" Ext. Sleeve

Clay

Very Soft

< 2

< 250

-

23.5

19.2

Clay

Soft

2-3

250-500

- 27.0

21.5

Clay

Medium Stiff

4-7

501-1,000

-

32.0

23.9

Clay

Stiff

8-15

1,001-2,000

-

34.5

26.9

Clay

Very Stiff

16-31

2,001-4,000

-

34.5

30.8

Sand

Very Loose

< 3

-

26-30

33.0

24.2

Sand

Loose

4-9

-

28-34

33.0

24.2

Sand

Medium

10-29

-

30-36

34.0

26.3

Sand

Dense

30-39

-

34-40

34.5

27.2

(1) ‐ Retrofit brackets shall be used for support of structures that are considered to be fixed from translation. Structures that are not fixed from translation shall be braced in some other manner prior to installing retrofit bracket systems.

(2) ‐ Allowable capacities are based on continuous lateral soil confinement in soils with SPT blow counts as listed. Piles with exposed unbraced lengths or piles placed in fluid soils should be evaluated on a case by case basis by the project

(3) ‐ Allowable capacities consider a loss in steel thickness due to corrosion. Scheduled thickness losses are for a period of 50 years and are in accordance with ICC‐ES AC358.

(4) ‐ Allowable capacities assume a concrete footing with a minimum compressive strength (f'c) = 2,500 psi.

(5) ‐ Allowable capacities with FS350BV retrofit bracket.

-- View Our Push Pier System Product Specifications document --

Foundation Supportworks Model 350 Pier System Specifications

  • Bracket: Weldment manufactured from 0.38”, 0.50”, and 0.63” thick steel plate, Yield strength = 36 ksi (min.), tensile strength = 58 ksi (min.).
  • External Sleeve: Ø4.000” x 0.226” wall x 48” long with sleeve collar welded to one end. Yield strength = 50 ksi (min.), tensile strength = 62 ksi (min.).
  • Pier Starter Tube:Ø3.500” x 0.165” wall x 50” long, triple-coated in-line galvanized. Yield strength = 50 ksi (min.), tensile strength = 55 ksi (min.). Ø4.000” x 0.226” wall x 1” long friction reducing collar welded to one end.
  • Pier Tube: Ø3.500” x 0.165” wall x 36” long, triple-coated in-line galvanized. Yield strength = 50 ksi (min.), tensile strength = 55 ksi (min.). Ø3.125” x 0.180” wall x 6” long internal coupler at one end with 3” extending out of pier tube.
  • Pier Cap: 4.00” wide x 8.50” long x 1.25” thick plate with pier locator plate welded to one side. Yield strength = 50 ksi (min.), tensile strength = 65 ksi (min.).
  • All-Thread Rod: Ø7/8” x 18” long, zinc plated. Grade B7, tensile strength = 125 ksi (min.).

-- View Our Push Pier System Product Specifications document --

Foundation Supportworks Model 350 Capacity Summary

Soil Strength Parameters(2)

Allowable System Capacity (1,2,3,4,5) (kips)

Soil Type

Consistency/Relative Density

SPT, N-value (blows/ft)

Cohesion (psf)

Friction Angle (degrees)

Clay

Very Soft

< 2

< 250

-

32.5

Clay

Soft

2-3

250-500

- 36.5

Clay

Medium Stiff

4-7

501-1,000

-

41.5

Clay

Stiff

8-15

1,001-2,000

-

43.5

Clay

Very Stiff

16-31

2,001-4,000

-

43.5

Sand

Very Loose

< 3

-

26-30

43.5

Sand

Loose

4-9

-

28-34

43.5

Sand

Medium

10-29

-

30-36

44.0

Sand

Dense

30-39

-

34-40

44.0

(1) ‐ Retrofit brackets shall be used for support of structures that are considered to be fixed from translation. Structures that are not fixed from translation shall be braced in some other manner prior to installing retrofit bracket systems.

(2) ‐ Allowable capacities are based on continuous lateral soil confinement in soils with SPT blow counts as listed. Piles with exposed unbraced lengths or piles placed in fluid soils should be evaluated on a case by case basis by the project

(3) ‐ Allowable capacities consider a loss in steel thickness due to corrosion. Scheduled thickness losses are for a period of 50 years and are in accordance with ICC‐ES AC358.

(4) ‐ Allowable capacities assume a concrete footing with a minimum compressive strength (f'c) = 2,500 psi.

(5) ‐ Allowable capacities with FS350BV retrofit bracket.

-- View Our Push Pier System Product Specifications document --

Foundation Supportworks Model 400 Pier System Specifications

  • Bracket: Weldment manufactured from steel plates with integrated pipe sleeve. Steel plate: 0.38” and 0.50” thick steel plate, yield strength = 36 ksi (min.), tensile strength = 58 ksi (min.). Pipe sleeve: Ø4.50” x 0.237” wall x 14.50” long. ASTM A53 Grade B Type E & S, yield strength = 35 ksi (min.), tensile strength = 60 ksi (min.).
  • Pier Starter Tube:Ø4.00” x 0.226” wall x 36” long. ASTM A500 Grade B or C, yield strength = 50 ksi (min.), tensile strength = 62 ksi (min.). Ø4.50” x 0.237” wall x 1” long friction reducing collar welded to one end.
  • Pier Tube:Ø4.00” x 0.226” wall x 36” long. ASTM A500 Grade B or C, yield strength = 50 ksi (min.), tensile strength = 62 ksi (min.). Ø3.50” x 0.216” wall x 8” long internal coupler at one end with 4” extending out of pier tube.
  • Pier Cap: 4.00” wide x 8.50” long x 1.25” thick plate with pier locator plate welded to one side. ASTM A572 Grade 50, yield strength = 50 ksi (min.), tensile strength = 65 ksi (min.). All-Thread Rod: Ø0.875” x 18” long, zinc plated. ASTM A193 Grade B7, tensile strength = 125 ksi (min.).

-- View Our Push Pier System Product Specifications document --

Foundation Supportworks Model 400 Capacity Summary

Allowable System Capacity: 39,000 lbs. (with FS400BV Bracket)

Notes:

1.Retrofit brackets shall be used for support of structures that are considered to be fixed from translation. Structures that are not fixed from translation shall be braced in some other manner prior to installing retrofit bracket systems.

2.Concrete bearing assumes a minimum compressive strength (f’c) of 2,500 psi. Local concrete bending and other local design checks should be evaluated on a case by case basis by the project engineer.

3.Mechanical capacity is based on continuous lateral soil confinement in soils with SPT blow counts ≥ 4. Piles with exposed unbraced lengths or piles placed in weaker or fluid soils should be evaluated on a case by case basis by the project engineer.

-- View Our Push Pier System Product Specifications document --


Push Pier Design Considerations

Design Considerations

Push piers are installed directly adjacent to the existing structure utilizing side-load brackets. This introduces eccentricity into the system. The Model 288 Push Pier System incorporates an external sleeve at the top of the pier to aid in resisting the bending forces generated by this loading condition. This helps preserve the axial compressive capacity of the pier shaft. The external sleeve extends through and below the foundation bracket to essentially create a bracket that is 48 inches tall.

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 near the surface. 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. A modified, lower capacity system is also available with a shorter, 30-inch long sleeve for low headroom applications.

Friction Reducing Collar

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.

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

Serving MT and WY including the Greater Bozeman area
Cities in Beaverhead County, MT
Dillon
Wise River

Cities in Big Horn County, MT
Busby
Crow Agency
Decker
Garryowen
Hardin
Lodge Grass
Saint Xavier
Wyola

Cities in Broadwater County, MT
Radersburg
Toston
Townsend
Winston

Cities in Carbon County, MT
Bearcreek
Belfry
Bridger
Fromberg
Joliet
Red Lodge
Roberts
Roscoe

Cities in Carter County, MT
Alzada
Boyes
Hammond

Cities in Cascade County, MT
Belt
Cascade
Great Falls
Malmstrom Afb
Monarch
Neihart
Sand Coulee
Stockett

Cities in Chouteau County, MT
Highwood

Cities in Custer County, MT
Miles City
Volborg

Cities in Deer Lodge County, MT
Anaconda
Warm Springs

Cities in Fergus County, MT
Buffalo
Coffee Creek
Forest Grove
Grass Range
Lewistown
Moore

Cities in Gallatin County, MT
Belgrade
Big Sky
Bozeman
Gallatin Gateway
Manhattan
Three Forks

Cities in Golden Valley County, MT
Lavina
Ryegate

Cities in Granite County, MT
Drummond
Hall
Philipsburg

Cities in Jefferson County, MT
Boulder
Cardwell
Clancy
Jefferson City
Whitehall

Cities in Judith Basin County, MT
Geyser
Hobson
Moccasin
Raynesford
Stanford

Cities in Lewis And Clark County, MT
Augusta
Canyon Creek
East Helena
Fort Harrison
Helena
Lincoln
Marysville
Wolf Creek

Cities in Madison County, MT
Ennis
Harrison
Mc Allister
Norris
Pony
Sheridan
Silver Star
Twin Bridges
Virginia City

Cities in Meagher County, MT
Martinsdale
Ringling
White Sulphur Springs

Cities in Missoula County, MT
Bonner
Clinton
Condon
Frenchtown
Huson
Lolo
Milltown
Missoula
Seeley Lake

Cities in Musselshell County, MT
Musselshell
Roundup

Cities in Park County, MT
Emigrant
Gardiner
Livingston
Pray
Springdale
Wilsall

Cities in Petroleum County, MT
Winnett

Cities in Powder River County, MT
Biddle
Broadus
Olive
Otter
Powderville

Cities in Powell County, MT
Deer Lodge
Garrison
Gold Creek
Helmville
Ovando

Cities in Ravalli County, MT
Corvallis
Florence
Hamilton
Stevensville
Victor

Cities in Rosebud County, MT
Ashland
Birney
Colstrip
Forsyth
Ingomar
Lame Deer
Rosebud

Cities in Silver Bow County, MT
Butte
Divide
Melrose
Ramsay

Cities in Stillwater County, MT
Absarokee
Columbus
Fishtail
Nye
Park City
Rapelje
Reed Point

Cities in Sweet Grass County, MT
Big Timber
Greycliff
Mc Leod
Melville

Cities in Treasure County, MT
Bighorn
Hysham
Sanders

Cities in Wheatland County, MT
Harlowton
Judith Gap
Shawmut
Two Dot

Cities in Yellowstone County, MT
Acton
Ballantine
Billings
Broadview
Custer
Huntley
Laurel
Molt
Pompeys Pillar
Shepherd
Worden

Cities in Big Horn County, WY
Basin
Burlington
Deaver
Greybull
Hyattville
Lovell
Manderson
Otto
Shell

Cities in Park County, WY
Cody
Meeteetse
Powell
Yellowstone National Park

Cities in Teton County, WY
Alta
Jackson
Kelly
Moose
Moran
Wilson

Our Locations:

HelixPro Design Software
Veteran Owned Small Business
Yellowstone Structural Systems BBB Business Review