Repair and Rehabilitation
Design

Forensic Engineering/
Failure Investigation/
Collapses

Environmental Structures

Building Facades/
Curtain Walls

Parking Structures

Special Structures

Structural Engineering/
Design

Roofs, Plazas and Waterproofing

Formwork Analysis Design/Shoring-Reshoring Analysis

Foundations and
Geotechnical Investigation

UNION SQUARE
New York, NY

JERICHO UFSD
Jericho, NY

BAIS AHAVA
Queens, NY

TOMMY HILFIGER SOHO
New York, NY

New three-story 40,000 square foot retail and office facility. Building has a deep foundation system supported on drilled piles to avoid damaging non-pile supported adjacent buildings from de-watering operations.
The Owner required a deep cellar for its sales area since the building site had a small footprint. The site had been a pre-revolutionary war marsh land that had been filled in over the years. Two critical concerns were that the cellar would undermine the adjacent buildings which had shallow
basement foundations without piles, and secondly dewatering operations to construct the new foundation would affect the adjacent buildings ability to support their own weight without settlement. It was determined after critical geotechnical investigations that a drilled pile system would not impose any damage to the adjacent buildings and the use of a chemical grout would permit sufficient dewatering to occur without affecting the adjacent structures. 9.625-inch drilled minipiles of 80 ton capacity were drilled through the marsh to rock approximately 100 feet below. A Dwidag high strength 150 ksi steel rod was used and concrete strength was f’c=4000 psi at 28 days. The rock socket was 4 feet deep.