Nasser Marafi

Research

My research involves studying the impact of large magnitude earthquakes on structures in the Pacific Northwest. As part of my PhD research, I worked with a team of researchers that are simulated ground motions using physics-based 3D models of a large section of the Pacific Northwest. These models used seismic wave velocities to describe the geological structure of the Cascadia subduction zone and surrounding region, including several deep sedimentary basins. The generated motions, which are produced across the extensive model region represent multiple rupture realizations of possible M9 Cascadia subduction zone events. These motions tend to have long durations, and locations on deep basins tend to see amplification of the long period spectral accelerations.

Ground Velocity of Simulated M9 CSZ Earthquake

We are currently using a suite of well-studied nonlinear multi-degree-of-freedom archetypical building models and also developing archetypical models that represent commonly built structures in the Pacific Northwest. These nonlinear numerical models will be of structures that range in period, geometry, and cyclic force-deformation properties. The results from the many ground motion simulations will generate large suites of ground motions that will be used to estimate engineering demand on these archetypes in a probabilistic framework.

Response of a 20-story concrete moment frame subjected to an M9 CSZ ground-motion

Response of a 40-story buckling restraint braced (BRB) structure subjected to an M9 CSZ ground-motion

Response of a 12-story reinforced concrete core wall structure subjected to an M9 CSZ ground-motion

The goal of this research is to assess the adequacy of current building code designs to provide adequate performance and propose necessary modifications to design practice to account for ground motion duration and basin amplifications. Finally, various archetype structures designed in the Pacific Northwest are assessed probabilistically against collapse under a Magnitude 9 Subduction Zone earthquake.

Résumé

Education


August 2018	University of Washington, Seattle, WA PhD Candidate in Civil Engineering Emphases in Structures and Earthquake Engineering Research Assistant - Hazard SEES - M9 Cascadia Subduction Zone Dissertation: Impacts of an M9 Cascadia Subduction Zone Earthquake on Structures Located in Deep Sedimentary Basinsd
August 2008	The Pennsylvania State University, University Park, PA Master of Architectural Engineering Emphasis in Structures
August 2008	The Pennsylvania State University, University Park, PA Bachelor of Architectural Engineering Emphasis in Structures Minor in Architectural Studies "Sede di Roma" Study Abroad Program in Rome - Summer 2006

Professional Qualifications and Experience


July 2010 - Current	Licensed Professional Engineer in the State of California License Number: C77076
Jan. 2020 - Current	Risk Management Solutions Inc., Newark, CA
Sept. 2013 - Dec. 2019	University of Washington, Seattle, WA
July 2010 - Sept. 2013	KEO International Consultants, Free Trade Zone, Kuwait
Sept. 2008 - July 2010	Buro Happold Consulting Engineers, New York, NY
May 2007 - Aug. 2007	KPFF Consulting Engineers, New York, NY

Awards


2018	Charles H. Norris Award
2018	EERI Graduate Student Paper Award
2016-2017	EERI/FEMA NEHRP Graduate Fellow

Publications

Academic Journals

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16	Molina Hutt, C., Zahedimazandarani, S. Marafi, N. A., Berman, J., and Eberhard, M. O. (2021) Collapse risk of tall steel moment-resisting frames in deep sedimentary basins during large magnitude subduction earthquakes. Engineering Structures. in-review
15	Wirth, E. W., grant, a., Marafi, N. A., and Frankel, A. D., (2021) Ensemble ShakeMaps for Magnitude 9 Earthquakes on the Cascadia Subduction Zone. Seismological Research Letters. doi: 10.1785/0220200240
14	Marafi, N. A., Grant, A., Maurer, B., Gunjan, R., Eberhard, M. O., and Berman, J. W., (2021) A Generic Soil Velocity Model that Accounts for Deeper Geologic Structure: Application to the Cascadia Region of North America. Soil Dynamics and Earthquake Engineering. doi: 10.1016/j.soildyn.2020.106461
13	Kourehpaz, P., Molina Hutt, C., Marafi, N. A., Berman, J., and Eberhard, M. O. (2021) Estimating Economic Losses of Mid-Rise RC Core Wall Buildings in Sedimentary Basins by Combining Empirical and Simulated Seismic Hazard Characteristics. Earthquak Engineering and Structural Dynamics. doi: 10.1002/eqe.3325
12	Yang, T., Marafi, N. A., Calvi, P. M., Wiebe, R., Eberhard, M. O., and Berman, J. W. (2020) Accounting for Spectral Shape in a Simplified Method of Analyzing Friction Pendulum Systems. Engineering Structures. doi: 10.1016/j.engstruct.2020.111002
11	Marafi, N. A., Makdisi, A. J., Berman, J. W., and Eberhard, M. O. (2020) Design Strategies to Achieve Target Collapse Risks for Reinforced Concrete Wall Buildings in Sedimentary Basins. Earthquake Spectra, doi: 10.1177/8755293019899965
10	Marafi, N. A., Makdisi, A. J., Eberhard, M. O., and Berman, J. W. (2020) Impacts of M9 Cascadia Subduction Zone Earthquake and Seattle Basin on Performance of RC Core-Wall Buildings. Journal of Structural Engineering, doi: 10.1061/(ASCE)ST.1943-541X.0002490
9	Wirth, E. A., Vidale, J. E., Frankel, A. D., Pratt T. L., Marafi, N. A., Thompson M., and Stephenson W. J. (2019) Source-Dependent Amplification of Earthquake Ground Motions in Deep Sedimentary Basins. Geophysical Research Letters, doi: 10.1029/2019GL082474
8	Li, T., Marafi, N. A., Sen, A. D., Berman, J. W., Eberhard, M. O., Lehman, D. E., and Roeder C. W. (2019) Seismic Performance of Special Concentrically Braced Frames in Deep Basin during Subduction Zone Earthquakes. Engineering Structures, doi: 10.1016/j.engstruct.2019.02.057.
7	Marafi, N. A., Eberhard, M. O., Berman, J. W., Wirth E. A., and Frankel A. D. (2019) Impacts of Simulated M9 Cascadia Subduction Zone Earthquakes on Idealized Systems. Earthquake Spectra, doi: 10.1193/052418EQS123M.
6	Marafi, N. A., Ahmed, K. A., Lowes, L. N., and Lehman, D. E. (2019) Sensitivity of Collapse Analysis for Reinforced Concrete Walls to Modelling Parameters. Journal of Structural Engineering, doi: 10.1061/(ASCE)ST.1943-541X.0002311.
5	Frankel, A., Wirth, E., Marafi, N. A., Vidale, J., and Stephenson, W. (2018) Broadband Synthetic Seismograms for Magnitude 9 Earthquakes on the Cascadia Megathrust Based on 3D Simulations and Stochastic Synthetics: Methodology and Overall Results. Bulletin of the Seismological Society of America, doi: 10.1785/0120180034.
4	Wirth, E., Frankel, A., Marafi, N. A., Vidale, J., and Stephenson, W. (2018) Broadband Synthetic Seismograms for Magnitude 9 Earthquakes on the Cascadia Megathrust Based on 3D Simulations and Stochastic Synthetics: Rupture Parameters and Uncertainty. Bulletin of the Seismological Society of America, doi: 10.1785/0120180029.
3	Xinsheng, Q., Motley, M. R., and Marafi, N. A. (2018) Three-Dimensional Modeling of Tsunami Forces on Coastal Communities, Coastal Engineering, doi: 10.1016/j.coastaleng.2018.06.008.
2	Marafi, N. A., Eberhard, M. O., Berman, J. W., Wirth E. A., and Frankel A. D. (2017) Effects of Deep Basins on Structural Collapse during Large Subduction Earthquakes. Earthquake Spectra. doi: 10.1193/071916EQS114M.
1	Marafi, N. A., Berman, J. W., and Eberhard, M. O. (2016) Ductility-dependent intensity measure that accounts for ground-motion spectral shape and duration. Earthquake Engng Struct. Dyn., doi: 10.1002/eqe.2678.

Conference Proceedings

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9	Marafi, N. A., Eberhard, M. O., Berman, J. W., Wirth, E. A., Frankel, A., and Vidale, J. (2018) Effects of Simulated Magnitude 9 Earthquake Motions on Structures in the Pacific Northwest. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted.
8	Molina-Hutt, C., Marafi, N. A., Eberhard, M. O., and Berman, J. W. (2018) Impact of Basin Effects during Subduction Zones in the Collapse Fragility of Existing Tall Buildings. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted
7	Marafi, N. A., Ahmed, K., Lehman, D., and Lowes, L. (2018) Collapse Analysis of RC Walls with Openings and Sensitivity of Model Parameter Uncertainties. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted.
6	Marafi, N. A., Li, T., Sen, A., Berman, J. W., Eberhard, M. O., Lehman, D., and Roeder C. (2018) Accounting for Demand Variability of Steel Braced Frames with a Combined Intensity Measure. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted.
5	Sen, A., Cakir, R., and Marafi, N. A. (2018) Seismic Risk Assessment and Educational Outreach for Schools in Central Washington. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted
4	Wirth, E., Frankel, A., Vidale, J., Stephenson, W., and Marafi, N. A. (2018) 3-D Simulations of M9 Earthquakes on the Cascadia Megathrust: Sensitivity and Uncertainty. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted
3	Frankel, A., Wirth, E., Vidale, J., Stephenson, W., and Marafi, N. A. (2018) 3-D Simulations of M9 Earthquakes on the Cascadia Megathrust: Methodology and Results. 11th National Conference on Earthquake Engineering, Los Angeles, CA. paper accepted
2	Marafi, N. A., Eberhard, M. O., and Berman, J. W. (2017) Effects of the Yufutsu Basin on Structural Response during Subduction Earthquakes. paper accepted.
1	Marafi, N. A., Berman, J. W., and Eberhard, M. O. (2017) A New Intensity Measure that Accounts for the effects of Spectral Acceleration, Duration, and Spectral Shape. 16th World Conference in Earthquake Engineering. paper accepted.

Posters

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7	Marafi, N. A., Makdisi, A., Berman, J., and Eberhard, M. (2019) Design Strategies that Account for the Impacts of a M9 Earthquake on RC Wall Structures in Deep Sedimentary Basins. poster accepted.
6	Marafi, N. A., Makdisi, A., Berman, J., and Eberhard, M. (2019) Impact of an M9 Cascadia Subduction Zone Earthquake on RC Core Wall Structures in Deep Sedimentary Basins. poster accepted.
5	Marafi, N. A., Makdisi, A., Berman, J., and Eberhard, M. (2019) Design Strategies that Account for the Impacts of a M9 Earthquake on RC Wall Structures in Deep Sedimentary Basins. poster accepted.
4	Marafi, N. A., Ahmed, K., Lehman, D., and Lowes. L. (2018) Collapse Analysis of RC Walls and Sensitivity to Constitutive Model Parameter Uncertainty. 11th National Conference in Earthquake Engineering. poster accepted.
3	Marafi, N. A., Berman, J. W., Eberhard, M. O., and Makdisi, A. (2017) Impacts of an M9 Cascadia Subduction Zone Earthquake on RC Core Wall Structures in Deep Sedimentary Basins. 2017 PEER Annual Meeting. poster accepted.
2	Marafi, N. A., Berman, J. W., Eberhard, M. O., Wirth, E., and Frankel, A. (2017) Design Strength Factors that Account for Basin Effects during Subduction Zone Earthquakes. 2017 EERI Annual Meeting. poster accepted.
1	Marafi, N. A., Berman, J. W., Eberhard, M. O., Vidale, J., Duvall, A., Abramson, D., Bostrom, A., and Frankel, A. (2015) Estimating Seismic Force Reduction Factors using Spectral Shape and Duration Intensity Measures. 2015 Structures Congress. poster accepted.

Media Mentions

My research featured in the press (not necessarily authored by me).

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6	Q13 Fox (KCPQ). "Sound bite on Q13 News at 5" 3 May 2019.
5	Seismological Society of America. "Reinforced concrete wall damage may be larger than expected in major Seattle earthquake." ScienceDaily, 24 April 2019.
4	Tom Banse. "'Bowl Of JELL-O Effect' could bring down tall buildings in the Big One, scientists say." KUOW, 13 March 2019.
3	David Jacobson. "New findings clarify the seismic risk in the Pacific Northwest." Temblor, 24 July 2018.
2	Paige Bartlett. "Simulated disasters." The Daily, 9 November 2017.
1	Hannah Hicky. "50 simulations of the ‘Really Big One’ show how a 9.0 Cascadia earthquake could play out." UW News, 23 October 2017.