EERI’s San Diego Regional Chapter is hosting a FREE webinar on the Application of Non-Ergodic Site Response Analysis to Seismic Retrofit Projects.
May 14, 2026
12:00 - 1:00 PM Pacific Time
| REGISTER HERE |
Non-ergodic site response analysis represents an advanced approach to characterizing ground motions for seismic design, accounting for site-specific effects beyond ergodic ground motion models (GMMs). While prior studies have primarily applied this method to SSHAC projects in the energy sector or new construction projects targeting the Maximum Considered Earthquake (MCER) risk level, very few non-SSHAC projects have employed non-ergodic methods, particularly in Southern California. As such projects are increasingly undertaken following recent changes in the NEHRP Provisions (Stewart et al. 2026), practical and technical issues are sure to arise for which best-practices will need to be defined. This webinar will present results from a study that documents processes and results for case examples from two seismic retrofit projects in Los Angeles, California. These projects consider hazard levels that are lower than the MCER level and include the Basic Safety Earthquake-2E (BSE-2E, 5% exceedance in 50 years) and BSE-1E (20% exceedance in 50 years) hazard levels. These projects apply non-ergodic methods in retrofit contexts, where cost-effective hazard mitigation is critical, by incorporating nearby recordings and hazard-consistent inputs to refine site response estimates. They also identify key hurdles to implementation—such as data availability, computational demands, and integration with existing codes—and propose practical strategies for overcoming them.
The evaluations follow ASCE 41-23, the 2026 Los Angeles City Building Code, and ASCE 7-22. The scope includes subsurface investigation with deep surface wave surface wave soundings and ground motion hazard analysis using the following methods: mapped parameters (ASCE 41-23 Section 2.3.2), site-specific hazard analysis using ergodic GMMs (ASCE 41-23 Section 2.3.3, ASCE 7-22 Chapter 21.2), hybrid ground response analysis (GRA) (ASCE 7-22 Chapter 21.1), GRA with hazard curve convolution (Bazzurro and Cornell, 2004), and non-ergodic SRA (Stewart et al., 2017) using nearby strong motion records and GRA. Each of these methods’ results are compared and commentary is provided on use cases for each method."
One Professional Development Hour will be provided FREE to EERI members and can be purchased for $25 for non-members.
Note: To register for this free webinar, you will need to sign into your account on EERI’s new member portal. If you haven’t yet reset your password to do so, view the instructions here.
