Ellis Island Seawall Rehabilitation
Location
Ellis Island, New Jersey
Client
National Park Service
Services Provided
Geotechnical Engineering Design
Geo-Environmental Engineering Design
Geostructural Engineering Design
Construction Monitoring
Permitting
Historic Preservation Actions
Retaining Wall Stabilization
Project Overview
Ellis Island is a 28-acre, U-shaped island located in the entrance to the New York Harbor. Through the years, this gateway to the new world was enlarged from its original 3.3 acres to 27.5 acres mostly by fill obtained from ship ballast, and possibly excess earth from the construction of the New York City subway system. It is now comprised by what are referred to as Islands 1, 2 and 3. In 1965, Ellis Island was declared part of the Statue of Liberty National Monument. Starting in 1984, Ellis Island underwent a $160 million restoration, the largest historic restoration in U.S. history. The Main Building was reopened to the public in 1990 as the Ellis Island Immigration Museum.
The island's seawall is over 6,700 lf and was built of various construction techniques between 1913 and 1934. The seawall construction techniques varied from a pre-cast concrete gravity wall on cement bags, concrete counterfort wall on timber cribbing, concrete gravity wall on timber piles, to anchored concrete sheetpiles. Today, the seawall shows varying degrees of deterioration, all of which have resulted in accelerated deterioration of the seawall itself and erosion from behind the seawall compromising the seawall stability.
As a subconsultant, Schnabel visually surveyed the seawall condition and to propose rehabilitation and preservation actions. Schnabel also performed a visual and GPR survey of the seawall, as well as a review of historic documents. Schnabel provided design and construction observation of major seawall stabilization measures at several locations around the island, and was retained to provide coastal & sediment removal permits for this project.