OVERVIEW:
The development at 125 3rd Street involved the construction of a 14-story mixed-use building and an adjacent 8-story structure in Brooklyn’s Gowanus neighborhood. Designed by Fogarty Finger and developed by Prospect Developers, the site delivers 130 units and 12,750 square feet of ground-floor retail space.
PROJECT TEAM:
Structural Engineer: DeSimone Consulting Engineers
Geotechnical Engineer: Langan Engineering
Installation Contractor: East Coast Bulkheading
CHALLENGES:
The development site presented multiple foundation challenges. The most significant was the presence of highly contaminated soils, which required that any spoils or removed material would need extensive remediation. This would introduce additional costs and permitting requirements. Additionally, due to the adjacent structures, equipment access was limited in certain areas of the site, and vibrations could not
be tolerated.
SOLUTION:
To address these constraints, STELCOR Drilled-In Displacement Piles were selected as they are installed without spoils, eliminating the need for costly and time-consuming contamination remediation. The compact and vibration-free system also allowed work to proceed safely near existing structures. As a result, foundation installation was completed ahead of schedule, contributing to overall project completion in just 9 months.
DESIGN LOADS:
Compression: 110 tons
Tension: 27 tons
Lateral: 4 tons
PILE DETAILS:
Type: STELCOR 1600
Nominal Grout Diameter: 16 inches
Steel Core: 5-1/2" O.D. 0.361" W.T.
Quantity: 272 piles
Length: 69 feet
SOIL PROFILE:
The soil at the site generally consisted of urban fill, common in redeveloped areas. This layer was followed by sand mixed with varying amounts of silt and gravel, followed by a thick layer of soft clay, which presented compressibility concerns. At greater depths, another sand layer was encountered, also mixed with silt and gravel, offering better load-bearing properties.
