Seismic base isolation in practice: The California experience

Seismic base isolation systems of various forms and features have been implemented in design of many new buildings and in rehabilitation of several existing structures. Currently, at least in California, the seismic isolation option is seriously considered at the onset of design of any hospital or health care facility project. While the design and implementation of seismic isolation systems seem to have been successful, there exist a multitude of problems which need to be addressed during each of the design, manufacturing, and construction processes to ensure a satisfactory end-result. The authors have been involved as structural and geotechnical engineers, as well as peer reviewers and plan checkers for many of the landmark California seismic isolated structures. This paper will provide a summary of state-of-the-practice and its problems for seismic isolated building structures.