Deep Foundation Helical Anchor For Steel Tower Structure housing construction

Helical piles can serve as either end-bearing or side-friction elements. In the case of end-bearing piles, the lead section is advanced through unsuitable soil layers until it reaches a suitable bearing stratum, achieving a predetermined design torque value. For side-friction piles, "digger plates" are installed between each section to create an annular space around the steel shaft, which is then filled with grout as the pile is advanced. This process establishes a grouted bond with the surrounding soil, resulting in a helical micropile. Similar to a Drilled Micropile, a side-friction helical micropile is installed to a specified design depth.

Helical piles are particularly effective for foundation support or underpinning that requires low to moderate pile capacity. Other foundation options, such as Ductile Iron Piles or Drilled Micropiles, may offer greater design efficiency and cost savings by providing higher working capacities.

Additionally, helical piles can be utilized as anchors or tiebacks.

Helical piles require the design input of a professional engineer (P. Engineer). Some standard designs have been developed for the most common situations, but each case needs to be reviewed. To design a pile, the engineer reviews three factors:ndard designs have been developed for the most common situati   

Applied Load

The loads that the structure will apply to the pile it connects to. These loads include the dead load, live load, lateral loads, and seismic loading that the pile is being used to resist.

Soil Parameters

Soil strength is reviewed to make sure that it can withstand the load applied by the pile and helix plates.

Pile Capacity

The amount of load that a pile can resist. The pile shaft and connection are selected to resist the applied load. The helix plates are designed based on soil information to ensure that they are the right size.

Termination brackets transfer the load to the pile at the head. The termination bracket is connected to the foundation, typically by attaching it to or casting it into a concrete foundation, or directly to a steel grillage structure.

Round Shaft Helical l

Round Shaft Advantages

• Superior lateral stability
• Greater section modulus strength to resist twisting and deflection
• Patented cross-bolt connection
• Greater load capacities
• Easy to install
• Installs in any season
• Minimal soil disturbance
• Not affected by a high water table

Composition:

• A round hollow shaft 2 7/8″ thru 12 ¾” O.D. typical.
• Circular tapered plates (helices) are welded to the center of the shaft.
• Helix diameters can range between 6″ – 48″ with a thickness of 3/8″ – 1″.
• Helix pitch will range from 3″ – 6″.
• Galvanized or bare steel options available

Helical anchors are a deep foundation system. It consists of a central shaft of various diameters, thicknesses, and spiral plates. The diameters of helical plates depend upon soil conditions and loading.