Civic Redevelopment in Portland, Oregon, for Gerding/Edlen Development Company
GeoDesign provided geotechnical engineering services for the 16-story condominium tower and 5-story apartment building.  The project also includes a 3-floor, below-grade parking garage beneath the apartments.  Approximately 40 feet of random fill overlies alluvial native soils across the entire site and an approximately 100-year-old, 60-inch-diameter, masonry sewer is present at a depth of 50 feet below the condominium tower.  The condominium tower is supported on high capacity, 11.75-inch-inside-diameter pipe piles, except in the vicinity of the sewer pipe.  To prevent damage to the sewer, high-capacity drilled shafts support the building within 10 feet of the pipe.  The apartment building will be supported on a mat foundation.  We also provided geotechnical design recommendations for shoring the 35-foot-deep excavation adjacent to an existing settlement-sensitive building for use in state-of-the-art "top down" construction.  Conventional soldier pile and tieback shoring methods have been implemented at other locations.