Deer Island Digesters
SGH worked with the Electric Boat Division of General Dynamics and Perini to develop the egg-shaped digester tanks for the Deer Island Water Treatment Facility. The project included eight 3-MG egg-shaped digesters and two 3-MG gas storage tanks. SGH evaluated the digesters and storage tanks for conformance with seismic design requirements and designed the reinforced concrete ring walls that support the digesters and gas storage steel tanks. SGH performed finite element analyses, including fluid-structure interaction for horizontal and vertical ground motion, determined stresses in the tank wall from the impulsive components, and computed the convective components of liquid accelerating within the steel shell. The SGH design of the concrete ring wall included an innovative anchorage of the steel tank base plate to the ring wall for transmitting the large overturning moment.