Event Date
The Millennium Tower in San Francisco, California, was developed between 2005-2009 with the original geotechnical report predicting 4 to 6 inches of settlement, and by 2014 had settled more than 14 inches. The differences in settlement led to legal proceedings initiated in 2015 by the homeowners, ultimately leading to mediation. Slate Geotechnical Consultants, Inc. worked with Simpson Gumpertz & Heger and John A. Egan to demonstrate the building met code criteria and safety-related performance goals. As a part of the legal proceedings, a voluntary foundation upgrade to install piles to bedrock was selected. This presentation includes an overview of the conditions contributing to building settlement and tilting, geotechnical analyses performed for the upgrade, and construction of the upgrade.
Bio
Nathaniel Wagner, PhD, PE, GE, is a San Francisco Bay Area-based geotechnical engineer. He has provided engineering support and managed geotechnical projects throughout California and the United States, including for subsurface utilities, power plants, earth and concrete dams, hospitals, building foundations, and forensic geotechnical engineering, as well as peer review of geotechnical engineering and foundation design aspects of structures. His areas of expertise include analysis of shallow and deep foundation systems, analysis of earth retaining systems, assessment of seismic hazards due to liquefaction, slope stability and seismic deformation potential of embankment dams, site response analysis, and numerical modeling of geotechnical and soil/structure systems.
Dr. Wagner earned his BS, MS, and PhD from the University of California, Berkeley, from 2007 to 2016. He has worked on the Millennium Tower project since 2016, and joined Slate Geotechnical Consultants, Inc. as a Project Engineer in 2019 shortly after it was formed to continue working with the founding Principals.