Ronald O. Hamburger, SE, Consulting Principal with Simpson Gumpertz & Heger has nearly 50 years’ structural engineering design, education, construction and failure investigation experience. He is a past President of the Structural Engineers Associations of Northern California, and California, as well as the National Council of Structural Engineering Associations and is a past chair of the Structural Engineering Certification Board. For more than 30 years, he has been active in leading the development of structural engineering design guides and building code requirements. In 2015, he was elected to the National Academy of Engineering in recognition of this work.
Constructed in 2005-2009, the 58 story Millennium Tower, located at the corner of Fremont and Mission Streets in San Francisco, has settled more than 17 inches and tilted nearly 30 inches to the northwest. Litigation initiated in 2016 with homeowners seeking damages from the original development team and other parties. Under negotiated agreement, a $100 million foundation upgrade has been completed to arrest building settlement and allow for gradual recovery of tilt. The upgrade, completed in August of this year, involved installation of 18 new piles, extending to bedrock, around the building’s perimeter. Mr. Hamburger will describe the building, the cause of its settlement, the upgrade and construction difficulties, and lessons learned.