Presentation Title:
Transforming the Seattle Waterfront
Abstract:
The Seattle Waterfront has experienced multiple transformations over its history, starting in the late 1800s as the city was established on the shoreline of a hill adjacent to a tidal flat. As the city grew, engineers and contractors modified the area including sluicing of the hills to fill in the tidal flat, constructing piers, buildings, a seawall, and a highway, and, more recently, tearing down that highway, replacing it with a tunnel, and renovating the waterfront to bring in new life and activity. The complex geology of Seattle, developed from glacial, volcanic, seismic, and river processes, as well as the changes that humans have made, provides unique geotechnical challenges to constructing foundations in this environment. Over the last 20 years, several major projects have been conducted along the waterfront including replacement of an aging seawall, excavation of one of the world’s largest bored tunnels, removal of a seismically vulnerable viaduct, and projects to provide new public spaces along the waterfront including a promenade, park, public piers, and an aquarium. Discussion of key
geotechnical aspects of some of these interesting projects illustrate the variety of conditions that can be expected when constructing foundations in the Downtown Seattle area. Monique Anderson is a Seattle-based geotechnical engineer who has participated in these projects over the last 20 years, supporting the City of Seattle and Washington State Department of Transportation in navigating our interesting geology and subsurface conditions and what we try to build on it and through it.