Major Ongoing Ground Motion Research Programs at PEER Yousef Bozorgnia, Ph.D., P.E. PEER, University of California, Berkeley PEER is coordinating three major ground motion programs Next Generation Attenuation (NGA) relationships for Central & Eastern: NGA-East Follow-up studies of ground motion prediction equations (GMPEs) for shallow crustal earthquakes in active tectonic regions: NGA-West 2 Global GMPEs for Global Earthquake Model (GEM) NGA- East Goal: To develop next generation Ground Motion Prediction Equations (GMPEs) for Central & Eastern US Stable Continental Regions (SCRs) Sponsors: NRC, EPRI, USGS, DOE How the Project was Planned Brainstorming Technical Workshops in 2007-2008 Two invitational and a pubic workshops Compiled a list of key technical issues and R&D projects to be addressed in the course of NGA-East The list was finalized through iterations Consensus was to develop Next Generation Models rather than updating PSHA implementation of the existing models NGA-East Technical Working Groups Working Groups Database: Compile a database of recorded motions from CEUS and other Stable Continental Regions (SCRs) Geoetchnical Engineering: Linear and nonlinear site responses; reference rock condition,… Working Groups Source-Site Path: Investigate geometrical spreading steeper than 1/R; Q; … Ground Motion Simulation: Generate calibrated & validated simulated GMs for CEUS to be used by GMPE developers Working Groups Sigma: To develop uncertainty models for GMPEs. It is a joint WG between NGA-East and NGA-West 2 Vertical Ground Motion: To recommend development of vertical GMPEs for CEUS, possibly by taking advantage of empirical data for V/H, … Working Groups GMPE Development Next generation attenuation models for CEUS; applicable to magnitude 4-8, distances of 0-1000 km 5% damped response spectra at periods 0.01 to 10 sec NGA-East is a SSHAC Level 3 Project SSHAC (Senior Seismic Hazard Analysis Committee) is a process: To ensure fully transparent project To ensure high quality research and final product Consistent with other related nuclear projects by NRC, EPRI, DOE,… Project Schedule Draft GMPEs to be ready for internal (SSHAC) review: GMPEs to be ready for review by various stakeholders (including USGS): By September 30, 2012 By September 30, 2013 Oct 1, 2013 - Sept 30, 2014: Sensitivity analysis, review, collect comments, adopt for various applications (including National Seismic Hazard Maps) Workshops… We will have numerous workshops As part of SSHAC process; and also to: To collect feedback and comments from the community To give information about the NGA-East project Next SSHAC workshop: Critical issues and data needs. On November 15-18, 2010 at UC Berkeley…please register at PEER web site (free of charge) and attend NGA-West 2 Project NGA-West 2 Follow-up of NGA-West 1 to address the issues and topics that we did not have opportunity to address in the previous phase And, update the NGA-West 1 models Funding agencies: California Earthquake Authority (CEA) Caltrans PG&E USGS FEMA NGA-West 2: Topics Finalize directivity model(s) for NGAWest Directionality issues for NGA-West GMPEs for vertical ground motion Recall, NGA-West 1 models were for horizontal motion Verification of NGA models for small magnitude data To reduce the conservatism of NGA-West 1 GMPEs for small magnitude data NGA-West 2: Topics Verification of NGA models for recent moderate and large magnitude events worldwide Compilation of the NGA-West 1 database was stopped in mid-2003 The new expanded database is larger by 70% (3,500 versus 6,000 recordings) 2004 Parkfied EQ, Wenchuan EQ (M 7.9), Italian EQs, Japanese Eqs, Baja EQ, … The most comprehensive empirical database, including metadata, ever compiled for shallow crustal EQs in active tectonic regions NGA-West 2: Topics Scaling NGA models for damping other than 5% Development of epistemic and aleatory uncertainty models (joint with NGAEast) Further development of site response in NGA Current NGA-West 1 site amplification factors are inconsistent with NEHRP factors Goal: To make NEHRP and NGA site amps consistent NGA-West 2: A Tentative Topic (Tentative—now becoming serious) Development of GMPEs for maximum direction horizontal ground motion NGA-West 2 Project Duration NGA-West 2 project will be completed by August 31, 2012 Global GMPEs for Global Earthquake Model (GEM) Project Goal: To select a suite of GMPEs for global and regional levels, by using a collaborative approach Duration: 24 months Team: 27 international experts from around the world Tasks Task 1: Definition of a consistent strategy of modelling ground motion consistency in model parameters consistency in site parameters Task 2: Compilation and critical review of GMPEs for: Shallow crustal earthquakes in active tectonic regions Stable continental regions Subduction regions Volcanic earthquakes Tasks Task 3: Selection a set of Global GMPEs Task 4: Inclusion of near-fault effects Task 5: Database of Recorded Waveform Task 6: Specifications for compilation of a global database of Soil Classification Summary Three major ground motion programs are currently coordinated by PEER: NGA-East NGA-West 2 GEM Each program has several supporting technical working groups Summary Many senior researchers, post-docs, graduate students, practitioners, end users, regulators, … are involved Coordination of such large programs would have been extremely challenging if wanted to carry it out outside of a national research center THANK YOU!