Waterfront Campus on Elliott Bay

A company campus is being developed on Elliott Bay and old lab buildings are being renovated. New structures are also being built as part of this project, including a parking structure and a berm for recreational green space which added too much overburden pressure to the soils and utilities in the area.

The site grade in the vicinity of the berm north of the P-1 Garage will be raised above existing grades as much as 8′. Lightweight fill was used to increase site grades without significantly increasing the overburden pressure on the existing soil and underground utilities. This would limit the settlement of underlying compressible silt and clay. An over-excavation of below-grade soil of 7′ took place since a 4′ thick layer of landscaping topsoil was planned at this berm. With the over excavation and placement of the cellular concrete, a zero-net in total weight was achieved.