Round, Square Shafts, New Construction, Standard Bracket, Heavy Duty, Flat, WalkWay Support, Post Brackets, Extensions - Iowa

Helical Pier System

Installation of Helical Pier Foundation Systems Helical piers (aka helical piles) are either square or round shafts with one or more helix bearing plates welded to the shaft. Helical piers are hydraulically “screwed” into load bearing soils. Grip-Tite’s helical piers have a true helix, meaning, the second and/or third helical plate follows the same path as the first when “screwed” into the soil. This minimizes the disruption of soil.

Helical piers can are used to repair an existing structure and also for new construction in place of micropiles, caissons, geopiers or other deep foundation systems. They can also be used instead of an over- excavation. The helical pier can be both time and cost effective.

When helical piers are used to repair an existing structure, they are “screwed” into the soil until a pre-determined torque is reached. A bracket is then placed on the steel shaft and positioned under the footing of the structure, transferring the load of the structure to the helical piers. The structure can then be stabilized or lifted back level.

Helical Piers have been in use for almost 200 years, and more recently have become more popular with engineers and contractors and used often in place of more costly alternatives.

	Round Shaft 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 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.
	New Construction Bracket
	Standard Bracket
	Heavy Duty Bracket
	Flat Bracket
	WalkWay Support Bracket
	Post Bracket
	Extensions Round Shaft and Square Shaft Extensions have lengths of 3, 5 and 7 foot sections.

Advantages

Lead sections and extensions can be configured to achieve design depth and capacity
Lead sections 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
Available with hot-dipped galvanized coating for added corrosion resistance

Retrofit

Lead sections of pier can be configured to achieve design depths and capacities
Minimal excavation required around 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 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

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 = 11,000 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)
Allowable capacity with retrofit foundation bracket = 40 kips

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)

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 – peformed 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

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Products

Helical Pier System