Fairfield Wastewater Treatment Plant

Case Study Location:

Project Specs:

  • Location: Fairfield, CT
  • Certified Installer: Foundation Stabilizers Inc. (FSI)
  • Engineer of Record (EOR): Stearns & Wheler, LLC
  • Helical Pile Specifications:
    – 342 MacLean Power Systems (MPS) Helical Piles
    – D10 (1.75″ Round Corner Square) Lead w/ 8″, 10″, 12″ Dia. Helices on a 7′ Shaft, a D10 Follower w/ 14″, 14″ Dia. Helices, & D10 Extensions
    – Average Depth of Helical Piles: 34′
    – Minimum Req’d Installation Torque of Helical Piles: 8000 ft-lbs
  • Ultimate Load(s):
    – 80 kips (Compression)
    – 80 kips (Tension)
Image Source > Google Earth

During the rehabilitation of the Town of Fairfield Wastewater Treatment Plant, three 105’ diameter clarifiers were to be constructed on a former municipal landfill. This brought into question the suitability of the soil for load bearing. To alleviate this concern, helical piles were chosen. The helical piles were installed to support the clarifiers in compression and in tension due the buoyancy of the tanks coupled with the high water table conditions on site. At each clarifier location, Foundation Stabilizers Inc. installed 114 piles. A total of 342, 1.75” (round corner square shaft) helical piles were installed to an average depth of 34.’