Winthrop, MA
MWRA Deer Island Wastewater Treatment Plant, Egg-Shaped Digesters
Scope/Solutions
The Deer Island Wastewater Treatment Plant, which is owned and operated by Massachusetts Water Resources Authority, removes pollutants from wastewater that originates in homes and businesses in the greater Boston area. Buchart-Horn, the Electric Boat Division (EBDiv) of General Dynamics, and Perini retained SGH to develop the seismic design for egg-shaped digester tanks and their supporting concrete structures.
SGH helped develop the seismic design for the eight 3-MG egg-shaped digesters and two 3-MG gas storage tanks. Highlights of our analyses include the following:
- Evaluated the structures of the digesters and storage tanks
- Designed the reinforced concrete ring walls that support the digesters and gas storage steel tanks, which included an innovative concept for the anchorage of the steel tank base plate to the ring wall used to transmit the large overturning moment.
- Performed finite element analyses that included fluid-structure interaction for horizontal and vertical ground motion
- Determined stresses in the tank wall from the impulsive components
- Computed the convective components of liquid accelerating within the steel shell
Project Summary
Solutions
New Construction
Services
Structures | Advanced Analysis
Markets
Infrastructure & Transportation
Client(s)
Buchart-Horn | General Dynamics
Specialized Capabilities
Seismic Engineering | Computational Mechanics
Key team members

Additional Projects
Northeast
MBTA Bus Repair Garage
The building includes three garage bays, offices, and locker facilities for the bus operators and repair staff. When an elevated concrete floor slab in one of the bays failed under the weight of a bus wheel, the MBTA retained SGH to investigate.
Northeast
MWRA, Blue Hills Covered Storage Design-Build Project
As part of an effort to eliminate open distribution storage resevoirs, Massachusetts Water Resources Authority sought to construct two covered drinking water storage tanks. SGH was the structural engineer for the design-build project.