John Jay College Expansion
New York, NY
2007 to 2010
- 191 caissons from 20” to 36” diameter
- Steel sheet piling
- Noise wall foundations
- Foundation installation adjacent to Amtrak’s NE corridor
- 20’ elevation change from the east to west side of the foundation
The project involved the construction of a foundation for a multiuse building to cover an approximate 100,000 SF area, including 191 caissons from 20″ to 36″ in diameter. The site was formerly that of a manufactured gas plant, and was comprised of a large amount of serpentine rock containing naturally occurring asbestos.
WHAT MADE THIS JOB COMPLEX
There were numerous complicating factors that made the safe and timely completion of this project challenging. Because the site was the location of a manufactured gas plant, it showed significant contamination and wet soil conditions. Caisson drilling was complicated by highly variable rock contours that meandered inconsistently throughout the site, unforeseen obstructions and debris. The unpredictable and often unsound rock required frequent steel splicing for caisson casing and reinforcing, as well as additional drilling to obtain adequate rock socket lengths to achieve required design tolerances.
HOW POSILLICO SOLVED IT
Posillico teamed with its Joint Venture partner, Gateway Industries Inc., to prepare its workforce to safely work in and around an extremely hazardous construction environment. Acute attention was paid to the various contaminated materials to be disposed of during construction. This minimized the impact to the work areas and project schedule. Since the plan required frequent track outages, we maintained diligence in our communication and collaborative working relationships with Amtrak personnel. We optimized our productivity during those outages to keep them as brief as possible.