Geotechnical Performance-Based Seismic Design for Tall Buildings in Seattle

抄録

Many of the advances in performance-based seismic design (PBSD) originated in Seattle, where a community of structural and geotechnical engineers specialize in tall building design and code development. This paper presents the history and practice of the geotechnical engineer’s role in performance-based seismic design of tall buildings in the greater Seattle area, including the characterization of the seismic hazard in the Puget Sound region and development of ground motions that are used in nonlinear dynamic structural models. The standard of practice for geotechnical seismic design continues to evolve with changes to codes and increased understanding of the seismic hazard and geologic conditions in the Puget Sound region. This paper provides an overview of the conditions under which PBSD is used and the evolution of design standards (from FEMA 356 through ASCE 7-16) used in practice. A technical overview is presented regarding the seismic setting in the Seattle area (including near-source effects of the Seattle Fault and basin amplification effects). Discussion of some of the technical aspects of PBSD, such as the development of site-specific spectra (uniform hazard, uniform risk, and conditional mean spectra), and the selection, scaling, and use of ground motion records for nonlinear response history analysis is included as well.