Our group does research in structural engineering, focusing on the impacts of extreme events on structures and communities, at the University of Colorado Boulder. Please explore this site to see what we are working on, find recent publications and contact us.
A group of wonderful people: Dr. Meera Raghunandan (Assistant Professor, IIT Bombay), Juan Olarte, Sarah Welsh-Huggins, Robert Chase, Travis Marcilla, Dr. Siamak Sattar (Research Structural Engineer, NIST)
New Drs. Sarah Welsh-Huggins and Cody Harrington, with Abbie Liel
With some other members of our research group: Jenny Ramirez and Juan Olarte
Cody Harrington successfully defended his thesis ADVANCEMENT OF PERFORMANCE-BASED EARTHQUAKE ENGINEERING FOR RC FRAME BUILDINGS: APPLICATION TO RETROFIT DESIGN AND CONSIDERATION OF VERTICAL GROUND MOTIONS on Nov. 15.
Congratulations, Cody!
Orlando Arroyo defended his thesis at Pontificia Universidad Catolica de Chile on "OPTIMIZACIÓN DEL DISEÑO DE UN EDIFICIO DE PÓRTICOS DE HORMIGÓN ARMADO PARA MINIMIZAR EL DRIFT"
Congratulations, Orlando!
Our paper on this topic is forthcoming in the ACI Structural Journal, co-authored with Curt Haselton, Greg Deierlein and Sarah Taylor-Lange. This paper represents an update version of the relationships in a 2007 PEER Report.
PhD students Sarah Welsh-Huggins is presenting her work at the 5th International Symposium on Life-Cycle Civil Engineering - IALCCE 2016 - in Delft, the Netherlands this week. Her paper is entitled "Is a Stronger Building also Greener? Influence of Seismic Design Decisions on Building Life-Cycle Economic and Environmental Impacts".
A paper coauthored with Derya Deniz (former postdoc), Erin Arneson, Shideh Dashti and Amy Javernick-Will will appear in Natural Hazards and has been published online. We explored the losses experienced in the City of Boulder in the 2013 Floods.
Two papers about reliability-targeted snow loads for roof design are forthcoming in the Journal of Structural Engineering. These cover approaches to determining ground snow loads where historical record is limited and topography is complex, and methods to ensure that roof reliability is consistent across different geographical contexts.
(A complete version of both papers with figures embedded will be available shortly).
Ratio of the computed reliability-targeted ground snow load to the 50-year ground snow load at 327 sites in Colorado.
Sarah Welsh-Huggins will be participating in a panel discussion on Wednesday, Sept. 28, hosted by CIRES’ Center for Science and Technology Policy Research (CSTPR), exploring the Catalyzing Advocacy in Science and Engineering (CASE) workshop.
The workshop, held over three days in the spring in Washington, D.C., connects young scientists with policy-makers for exposure to science advocacy as an integral component of influencing policy. Sarah attended last spring, as the winner of a campus competition for travel support.
Check out the full story here.
Abbie spoke on " Waiting for the big one: Simulations of infrastructure performance to inform seismic risk decision-making before the next earthquake". Chris McGann of the University of Canterbury was the other speaker in this session.
Moderator: Ricardo Taborda, Speaker: Chris McGann, Abbie Liel, Moderator and QuakeCore Deputy Director: Brendon Bradley
Check out Sarah's paper published this summer:
Building design and performance are increasingly being scrutinised from perspectives of both sustainability and hazard resistance. However, the approaches taken to consider these perspectives are disconnected; green building rating systems do not consider hazard resistance in their assessments, while performance-based engineering methods have tended to neglect consideration of environmental impacts. This study presents a framework to assess a building’s life-cycle performance in terms of social, environmental and economic impacts using probabilistic approaches, considering the possible occurrence of an earthquake or other extreme event. The framework is illustrated through a case study of an office building in Los Angeles, designed with and without different types of vegetated (green) roofs, and at risk from varying earthquake hazard scenarios. The case study results demonstrate trade-offs between upfront building costs, material choices, hazard resistance and environmental impact.
Several of us participated in the 2016 Natural Hazards Workshop in Broomfield, Colorado this week.
Sarah Welsh-Huggins, Ph.D. candidate, organized a panel session entitled Building Pathways to More Resilient and Sustainable Infrastructure. We had a great discussion on what it means to build resilient and sustainable infrastructure and communities. Many thanks to the panelists, Jamie Padgett, Sarah Welsh-Huggins, Beth Grote and Greg Guibert.
Panel at Natural Hazards Workshop.
The panel session also incorporated some artistry depicting our communities of the future.
Check out Cody's new paper on this topic on the publications page.
While many cases of structural damage in past earthquakes have been attributed to strong vertical ground shaking, our understanding of vertical seismic load effects and their influence on collapse mechanisms of buildings is limited. This study quantifies ground motion parameters that are capable of predicting trends in building collapse due to vertical shaking, identifies the types of buildings that are most likely affected by strong vertical ground motions, and investigates the relationship between element level responses and structural collapse under multi-directional shaking. To do so, two sets of incremental dynamic analyses (IDA) are run on five nonlinear building models of varying height, geometry, and design era. The first IDA is run using the horizontal component alone; the second IDA applies the vertical and horizontal motions simultaneously. When ground motion parameters are considered independently, acceleration-based measures of the vertical shaking best predict trends in building collapse associated with vertical shaking. When multiple parameters are considered, Housner intensity (SI), computed as a ratio between vertical and horizontal components of a record (SIV/SIH), predicts the significance of vertical shaking for collapse. The building with extensive structural cantilevered members is the most influenced by vertical ground shaking, but all frame structures (with either flexural and shear critical columns) are impacted. In addition, the load effect from vertical ground motions is found to be significantly larger than the nominal value used in U.S. building design.
Sarah presented a poster on this topic at the EERI Annual meeting in San Francisco in April, 2016, examining the tradeoffs associated with building stronger or more ductile. Talk to Sarah for more details (sarah.welshhuggins@colorado.edu)!
Check out this story by Matt Smith at VICE News.
Thanks to all who came to our research group and friends get-together this week. I continue to be inspired by all of the students and postdocs I get to work with.
Back row: Jakub Valigura, Sarah Welsh-Huggins, Jenny Ramirez, Abbie, Becca Scheetz, Juan Olarte, Travis Marcilla; Front row: Balaji Paramasivam, Cody Harrington, Robert Chase, Taojun Liu .
Thanks to all the prospective students who joined us at CU on March 4, and to my current students for sharing about their work. If you didn't get a chance to visit, please feel free to contact me at abbie.liel@colorado.edu.
Abbie, Cody Harrington and Robert Chase, with Cody, Rob and Travis' poster at the poster session for visiting students.
Our friends at the Structural Engineers Association of Northern California (SEAONC) have sponsored a nationwide study of compensation, employee engagement, and career satisfaction for structural engineers.
The goals of this study are two-fold: to understand the keys to employee engagement/retention, and to identify gender-related obstacles at various stages in a structural engineer's career. The overarching objective is to identify ways in which firms can adapt their practices to retain an engaged and productive workforce.
The online survey should take between 10-15 minutes to complete. It is anonymous and completely voluntary. The findings will be presented at various Structural Engineers Association (SEA) events, and other conferences.
Please fill out the survey to help gather the data we need to make our profession and workplaces even better. If you have any questions or comments, please direct them to SE3@seaonc.org.