Implementation of SCEC Research for Seismic Risk Reduction

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Summary. The Southern California Earthquake Center (SCEC) requests 2.6 years of funding to supportthree tasks that will translate SCEC's basic-research accomplishments into products for direct use inearthquake risk reduction. All of the tasks involve collaborations with earthquake engineers and otherend-user communities coordinated through SCEC's new Implementation Interface. A SCEC ProductReview Panel, comprising representatives from the USGS, CGS, and end-user organizations, will be setup to ensure that SCEC activities are coordinated with the USGS and CGS hazard programs and thatproducts are appropriately described, documented, and disseminated.Task 1: Produce ground-motion time histories for use in performance-based earthquake engineering(PBEE). Ground-motion time histories are necessary input into testing facilities and computer-baseddynamic analysis of structures that engineers will use to develop PBEE. Simulated broadband timehistories are needed to augment the limited set of recorded time histories close to large earthquakes.Under this task, we will use tested codes to produce a extensive database of simulated time historiesparameterized by magnitude, distance, and soil conditions. The database will facilitate geoscienceapplications by the NEES Consortium and the three NSF Earthquake Engineering Research Centers, andit will augment the Design Ground Motion Library Project, sponsored by the California Strong MotionInstrumentation Project and by the PEER-Lifelines (PEER-LL) Program.Task 2: Participate in Next Generation Attenuation (NGA) Project. The Next Generation Attenuation(NGA) Project, co-sponsored by SCEC, PEER-Lifelines and the USGS, will develop a new suite ofground-motion attenuation models for shallow crustal earthquakes. SCEC is already committed to thecurrent phase, NGA-E (Empirical), which aims to update attenuation relationships derived from recordedstrong motion data. This proposal requests support for SCEC's role in the next two phases, NGA-H(Hybrid), which will incorporate both simulated and recorded ground motions, and NGA-F, which willdevelop a tectonic-displacement model. NGA products will fulfill a clearly stated need of Caltrans, theCalifornia Energy Commission, and PG&E, and of earthquake engineering practice at large.Task 3: Produce Ground-Motion and Structural Simulations for Scenario Earthquakes in Los Angeles.Recent SCEC research has quantified major potential earthquakes on the Puente Hills blind thrust system.Task 3 will utilize this information to construct realistic scenarios for broadband ground motions from thePHT and other hazardous sources in the LA region, and it will engage earthquake engineers in assessingthe implications. A pilot study employing J. Hall's nonlinear structural simulation code will beundertaken to quantify the effects of a Puente Hills earthquake on buildings in downtown Los Angelesand use the results to evaluate current code provisions.Intellectual Merit. Reducing earthquake risk is a prime example of a system-level problem requiringbroad interdisciplinary collaboration and attention to emergent phenomena. The proposed program willaddress the issues of earthquake risk reduction from this system-level perspective, and it will advance thefundamental understanding of the relationship between earthquake source physics and resulting groundmotions -- a major goal of the SCEC research program.Broader Impacts. The proposed program will apply SCEC basic research to guide the development ofthe new ground-motion prediction models and ground-motion time histories used by researchers andpractitioners of earthquake engineering and risk assessment. Through the close coordination with NSFsponsoredearthquake engineering activities (see attached letters), this project can be expected to have anationwide impact on how basic geoscience is utilized to reduce seismic risk.