Keller installed two jet grout bottom seals to keep a dry excavation for underground fuel storage tanks and a pump station at Northwell Health’s Bay Shore campus expansion
The project
To increase capacity and enhance the programs available to their community, South Shore University Hospital constructed a 190,000 SF pavilion. To maximize the available space, two 20,000-gallon fuel storage tanks and a water pumping station were constructed below-grade.
The geotechnical engineer recommended 60 ft-long sheet piles to support the 12 ft and 18 ft excavations, reaching a supporting clay layer that would seat the cofferdam. However, due to the high water table, a groundwater cutoff solution was required to keep the excavation dry.
To provide the groundwater cut-off, Keller installed jet grout columns to create two bottom seals for the tank location and the pumping station. In total, 60 6-ft-diameter and 26 10-ft-diameter jet grout columns were created to seal the excavations.