Helical Piers FAQ’s

What is a helical pile?

A helical pile, also known as a screw pile or helical pier, is a deep foundation system used to support structures. It consists of a central steel shaft with one or more helical plates (similar to screws) welded to it. The pile is driven into the ground by rotating it, which allows the helical plates to pull the pile deeper into the soil.

How are helical piles installed?

Helical piles are installed by rotating the shaft of the pile with a hydraulic drive head mounted on an excavator or other machinery. As the shaft rotates, the helical plate advances into the ground, “pulling” the shaft with it. This action is much like a wood screw.

How far apart should helical piles be spaced?

Helical piles should be spaced at a minimum of three times (3x) the diameter of the largest helical plate, center to center. We typically use the largest helical plate, so for a lead section with an 8”/10”/12” helix configuration, the minimum spacing should be 3 x 12” = 36” center to center. 

The helical pile minimum spacing is only important down at bearing depth where the helical plates are, so if you have multiple piles under a pile cap and you want to minimize the area of the pile cap, you can typically install the helical piles at a batter (angle) to get the separation you need at bearing depth and the piles can be terminated in a smaller footing. If the helical piles do have to be installed closer than the minimum, you can use normal group effect formulas to de-rate the capacities accordingly.

Why does CHANCE offer four different shaft types?

CHANCE® offers four (4) different shaft types because not all soil conditions are conducive to every type. For instance, some soil conditions are too hard for an all-pipe shaft pile to install effectively, so a square shaft pile or even a combination pile would be a better and more efficient choice in harder soil conditions. By contrast, in weak/loose soil conditions that will have appreciable compressive loads, one of the round shaft options most likely will be the best choice.

Equipment Use?

We utilize Mini-excavators equipped with hydraulic torque heads to install helical piers on both large and small projects efficiently. This method is ideal for commercial and residential foundations where access can be limited, to reach the designed torque and depth readings. We record boring logs for each project, and they are available upon request.

Bidding And Estimating?

We offer free bids to clients or contractors. It is required for every customer to conduct a soil test/report and have a qualified engineer design the necessary helical heads, installation method, minimum torque, and estimated depth.