Helical Pier Foundation

Intro

Helical piers are essentially augers stuck into the ground, which serve as a foundation.

Basic Calculations

Take a 3" helical pier that can hold 12,000 lb/sf on rock or 1500 lb/sf on soft clay, with a safety factor of 2 [1].

• 7000 ft lb torque for screwing 8" diameter helix in [2]
• note that if the pier has 2 helices, that doubles the load bearing capacity! You can stack the helices, but need enough space between the helices.
• Helix is .217" pipe, 3" diameter. Steel Weight Calculator sez it's