Queens Plaza Residential Development
Long Island City, NY
2014 to 2016
- Drilled Caissons
- Steel Sheet Piling
The Queens Plaza Residential Development was a NYS Brownfield site which consisted of Creosote impacted soil. The scope of our work entailed installing support of excavation (secant pile wall, soldier piles, tiebacks, sheet piles), dewatering, excavating of roughly 126,000 tons of impacted soil (some of which was excavated within a Negative Pressure enclosure), soil mixing for remediation, drilling 500 piles, forming and pouring pile caps and foundation slab/walls for three high rise residential towers.
WHAT MADE THIS JOB COMPLEX
There was an abandoned cemetery from the time of the original Dutch settlement situated on the property, with an onsite archaeologist overseeing the excavation. The environmental remediation was performed concurrently with the foundation work. The Negative Pressure Enclosure was then relocated without the assistance of a crane due to proximity issues with the MTA. There were underground and overhead subways bordering the site. The extent of contamination was far greater than previously thought, forcing the excavation to go significantly deeper. Soil mixing was used for the deepest contamination. MTA restrictions limited the use of air actuated pile hammers within the MTA influence line. Scheduling was also problematic as schedules were very tight requiring the crews to work two shifts and weekends.
HOW POSILLICO SOLVED IT
Posillico was able to mobilize four large diameter drill rigs and three minipile rigs to attack the complex foundation and SOE challenges for the project. Posillico brought the expertise of working with high level contamination remediation, which enabled it to construct the Negative Pressure Enclosure (Tent) under tight conditions with minimal equipment to limit the impact on the schedule. Posillico was able to propose, design, and perform the soil mixing operation in order to solve problems with the deep contamination. Posillico was able to work in extremely tight conditions with specialty minipile rigs to install one of the smallest diameter secant pile walls constructed in North America.