[STRUCTURAL] Helical Piles and Frames for Disaster-Resistance
Point Pleasant, NJ
Flood-resistant, wind-resistant construction to meet new FEMA guidelines
RENOVA installed a combination of helical piles, a concrete grade beam, and a steel moment frame to provide an innovative, structurally sound, and complete foundation that would safely and cost-effectively comply with FEMA’s newly-released Base Flood Elevations and Coastal Construction Guidelines. The Guideline requirements include the capacity to avoid flood loads caused by flood waters, often with waves, and resist wind loads caused by 120mph sustained winds. The simplicity and constructability of the design ensured that the engineer’s specifications would be achieved in the field. The steel galvanized foundation members are corrosion-resistant for a minimum of 75 years, made in America, and manufactured with an ISO9001-certified quality control system.
Helical piles provide the deep foundation component and provide up to 100 kips of compression loads. The piles were installed to 42’ below grade with a hydraulic drive head and limited access machinery, which requires only 8’ of overhead clearance and creates no vibration, whereas the installation machinery for conventional wooden pilings requires virtually unlimited headroom and can distress nearby structures due to the vibrations. A grade beam was then poured to interlock the helical piles at grade, distributing the lateral loads uniformly across the piles and providing a foundation to secure the moment frame.
The moment frame is comprised of steel beams and columns that, when rigidly connected, yields an immense capacity to resist lateral forces. Moment frames span longer distances than conventional wood beams, thereby requiring fewer columns and fewer piles, resulting in larger functional space. Moment frames do not require above ground bracing which can trap debris in the event of a flood.
The innovative designs that incorporate helical piles and a moment frame will play an important role in constructing disaster-resistant structures.