Helical Pier Systems

foundation repair

What Are Helical Piers Systems Used For?

Helical pier systems, also known as helical pile systems or helical anchors, are used to repair and stabilize failing foundations. These effective pier systems can also be used when constructing new foundations in soils that cannot support traditional foundations. Helical piers are hydraulically driven and screwed into competent load-bearing soils. Grip Tite’s helical piers have true helix-shaped flight(s) welded to a central shaft to provide specified design capacities in both tension and compression applications.

At Grip-Tite, we make it easy to get the foundation repair products you need to keep your home or business safe. Our team has set the standard in the foundation repair industry for more than 100 years. When you want quality you can count on

ICC-ES Evaluated

An ICC-ES Report is a document that presents the findings, conclusions, and recommendations from a particular evaluation. ICC-ES Reports verify that new and innovative building products comply with code requirements. ICC-ES Reports provide information about what code requirements or acceptance criteria were used to evaluate a product, and how the product should be identified, installed and much more.

Specifications

Helical pier/anchor tube

2.875-inch Outside Diameter (O.D.) x 0.262-inch wall tube steel, ultimate tensile strength = 58,000 psi (min.), yield tensile strength = 50,000 psi (min.)
Torque Strength Rating = 9,000 ft.-lb.
Torque Correlation Factor (Kt) = 9 ft-1
Connecting Bolts
0.75-inch diameter Heavy Hex Machine Bolt (SAE J429 ‘ Grade 8)
Weld
E70 ‘ minimum tensile strength = 70,000 psi
Ultimate axial capacity based upon installation torque = 100 kips (tension/compression)
Allowable axial capacity based upon installation torque = 50 kips (FOS = 2)

New Construction Bracket

3.5-inch O.D. x 0.300-inch wall (ASTM A500, Grade C)
4.0 inches x 8 inches x 1-inch thick plate steel (ASTM A-36)
Connecting Bolts
0.75-inch diameter Heavy Hex Machine Bolt (SAE J429 ‘ Grade 8)
Weld
E70 ‘ minimum tensile strength = 70,000 psi
Allowable axial capacity = 50 kips (compression), 44 kips (tension)
Allowable capacity with retrofit foundation bracket = 40 kips

Retrofit Foundation Bracket

Bracket Tube
3.875-inch O.D. x 3.125-inch Inside Diameter (I.D.) x 10-inch long DOM mechanical steel tubing conforming to ASTM 513 ‘ Type 5 / Grade 1026. Ultimate tensile strength = 100,000 psi (min.), yield tensile strength = 90,000 psi (min.)
Angle Bracket
0.5-inch thick flat plate conforming to ASTM A-36 hot rolled steel bent to form a 90 degree angle with equal sides of approximately 8 inches. Ultimate tensile strength = 58,000 psi (min.), yield tensile strength = 36,000 psi (min.)
Bracket Support Strap
0.375-inch thick x 3 inches wide x 21.25 inches flat bar conforming to ASTM A-36 hot rolled steel which is bent into a “horseshoe” shape around the bracket tube. Ultimate tensile strength = 58,000 psi (min.), yield tensile strength = 36,000 psi (min.
Top Plate
0.75-inch thick x 5.5 inches wide x 9.5 inches long conforming to ASTM A-36 hot rolled steel. Ultimate tensile strength = 58,000 psi (min.), yield tensile strength = 36,000 psi (min.)
Cap Plate
1.0-inch thick x 4.0 inches wide x 8.5 inches long conforming to ASTM A-36 hot rolled steel. Ultimate tensile strength = 58,000 psi (min.), yield tensile strength = 36,000 psi (min.)
Weld
E71T1, minimum tensile strength = 71,000 psi ‘ preformed by AWS certified welder
Threaded Rod
0.75-inch diameter x 12 inches long ASTM A311 ‘ Class B / Grade 8 Zinc Plated. Ultimate tensile strength = 150,000 psi, yield tensile strength = 130,000 psi

Engineering Information

Helical Pier Evaluation Report

ROUND VS SQUARE

The Two Types Of Helical Piers

Round Shaft Piers

Round shaft piers are best used in compression applications. These piers have a greater load capacity and lateral strength.

Round shafts are 2 7/8″ diameter, 3.5-inch diameter, and 4.5-inch diameter. The Round Shaft lead sections utilize 1, 2, or 3 helix flights which are 8″, 10″, 12″, and 14″ in diameter.

Square Shaft Piers

Square shaft piers are more appropriate for projects that require significant tensile strength or torque capacity.

Square Shafts are 1.5, 1.75, and 2.25 inch Round Corner Square (RCS). Square Shaft lead sections utilize 1, 2, or 3 helix flights which are 8″, 10″, 12″, and 14″ in diameter

installation

How Are Helical Piers Systems Installed?

To install helical piers, the helical flights are geometrically spaced along the shaft. This provides minimal disruption to the soils in which they are installed. Then, a foundation bracket is connected to provide support to the failing foundation, or specified terminations are connected to the installed shaft to offer support to new foundations. This provides your home’s foundation with anchor points and ensures that your foundation will remain strong in the fight against damage.

Installation Information

standard

Lead sections and extensions can be configured to achieve design depth and capacity
Lead sections are available in 2, 5, and 7-foot lengths
Extensions available in 3, 5, and 7-foot lengths
Extensions utilize rigid, three-bolt couplings
Helical piers available with single, double, and triple helix lead sections
Helix blade diameters of 8, 10, 12, and 14 inches

Retrofit

Lead sections of the pier can be configured to achieve design depths and capacities
Minimal excavation is required around the foundation area
Installs quickly with small or handheld equipment
Vibration-free installation (unlike traditional driven piles)
No wait ‘ piers installed year-round
Installs in areas with limited or tight access without generating spoils
Pier system installed below grade ‘ not visible once the installation is complete
Cost-effective ‘ gets a structure back on solid ground
Permanent solution ‘ prevents further vertical movement

New Construction

All-weather installation
Can be installed with either handheld or small equipment
Can be installed in areas of limited or tight access
Foundation concrete can be poured immediately following installation
Lead sections can be configured to achieve design depth and capacity
Cost-competitive versus other deep foundation alternatives
Vibration-free installation (unlike traditional driven piles)
Installs quickly without generating spoils