CEE Seminar (ZOOM): Performance-based Seismic Design - Today’s Approaches and a Vision for the Future

Abstract: Performance-based seismic design (PBSD) has been used for decades for the seismic retrofit of existing buildings and the design of new structures. Today’s PBSD approaches focus on providing a design that typically targets one of the following performance levels for one of several ground-shaking hazard levels:

• Operational
• Immediate occupancy
• Life safety
• Collapse prevention

The building code performance objective for new, ordinary (Risk Category II) buildings is to provide life safety for design earthquake ground shaking and collapse prevention for maximum considered earthquake (MCE) ground shaking. PBSD for new buildings typically targets a performance equivalent to a code-prescriptive design. An example will be presented; we used nonlinear response history analysis to fine-tune the seismic design and reduce construction costs. 

The example evaluated whether the building meets the intended performance objective of a low likelihood of collapse given MCE ground shaking. Moving beyond solely using collapse as the metric for whether a design is acceptable is the vision for the future. A FEMA-sponsored, Applied Technology Council-managed research effort has been underway for over 15 years developing the methodology. The results of this effort have been published in FEMA P-58 Seismic Performance Assessment of Buildings. The final portion of the presentation will focus on this new approach, which will allow engineers to estimate the following loss information for their buildings:

• Repair costs
• Repair time
• Unsafe placards
• Embodied energy and carbon
• Casualties

Bio: John Hooper is a senior principal and the director of earthquake engineering at Magnusson Klemencic Associates, a consulting structural and civil engineering firm in Seattle, Washington. He received his bachelor's degree in civil engineering from Seattle University and a master's degree from UC Berkeley. Hooper has over 30 years of engineering experience in the fields of renovation, earthquake engineering and structural analysis and has been involved in the majority of MKA’s performance-based seismic high-rise designs over the past 20 years. He is chair of the American Society of Civil Engineer (ASCE 7’s) Seismic Subcommittee and is a member of the Main Committee, and a member of the Building Seismic Safety Council (BSSC) NEHRP Provisions Update Committee. He also currently serves on AISC’s TC-3, TC-5 and Committee on Specifications.