The $1.1 billion Essex Crossing project will include over 1,000 new residences, 450,000 square feet of retail, 400,000 square feet of office space, community attractions, and green spaces. We have been providing geotechnical engineering, support of excavation (SOE), and construction services for almost all buildings being constructed by Delancey Street Associates. This includes L&M Development Partners, BFC Partners, and Taconic Investment Partners.
We performed subsurface investigations and developed cost-effective mat foundations for four buildings that rise up to 26 stories. One building, located at the corner of Delancey and Essex streets, had a sub-cellar level, a challenging core location, and subways located along two sides of the property.
Many of the sites were located adjacent to a subway station. We were responsible for obtaining approval from NYC Transit to construct the excavations and buildings. The proximity of a site to the subway can present challenges for designing SOE and foundation systems that will be acceptable to the NYC transit outside projects engineers.
The Solutions Unearthed
- Design of a cost-effective driven pile (pipe piles and Tapertubes) and drilled a micropile system. The cellar SOE included driven and drilled soldier piles with tiebacks and the sub-cellar SOE included a soil-cement mixed wall with internal bracing.
- At several locations, concrete piers were designed to bear on top of, or immediately adjacent to, the subway, so that adequate lateral support could be provided.
- We were intimately involved with all phases of excavation and foundation construction: working with the owners, construction managers, and contractors to address unforeseen conditions to reduce costly construction delays and stop work orders. At one site, a large area of the subway waterproofing—which is typically protected by a layer of cement—was unexpectedly found to be protected by fragile terracotta tiles. We observed the conditions and quickly designed a cost-effective system to secure the tiles during the excavation operations.