DESCRIPTION: The City of Keizer built a new water storage tank to serve the proposed Chemawa Station shopping center and surrounding area during periods of peak demand. The 0.5MG tank is a single-pedestal spheroid with a height of ±140 feet and a base diameter of ±38 feet. The tank is owned by the City, but was built on land owned by the Confederated Tribes of Grand Ronde and Siletz Indians. The site is south of Keizer Station.
SERVICE: Foundation Engineering completed the geotechnical investigation and site-specific seismic hazard study for the project. Foundation options included a mat foundation, drilled shafts and driven piles. Sixty, HP12x53 steel piles were selected in consultation with the structural designer. Foundation Engineering analyzed the axial, uplift, and lateral capacities of the piles and developed pile driving criteria. Foundation Engineering was also present during construction to observe the pile driving, evaluate pile hammers via WEAP analysis, and review Pile Driving Analyzer (PDA) data collected during test pile driving.