Ph.D candidate Robert Chase defended his Ph.D disseration on Tuesday November 13th!
Hazard Implications of the 2016 Mw 5.0 Cushing, OK Earthquake from a Joint Analysis of Damage and InSAR Data by Magali Barba-Servilla, Bridger W. Baird, Abbie Liel and Kristy Tiampo
Find the access to the full text through remote sensing here: https://www.mdpi.com/journal/remotesensing/special_issues/Infrastructure_Monitoring
Although it is well-established that large-scale wastewater disposal in the Arbuckle formation is linked to the recent rise in seismicity in Oklahoma, few studies in Oklahoma have shown surface deformation resulting from induced seismicity or from wastewater injection or both. In our two-part study, we observe both the surface deformation leading up to the November 2016 Mw 5.0 earthquake and its coseismic signal using a satellite radar technique known as Differential Interferometric Synthetic Aperture Radar (DInSAR). In the first half, we perform a spatiotemporal correlation analysis of DInSAR derived surface deformation, wastewater injection, and seismicity in Cushing, OK. In the second half of the analysis, we invert for the source of the November 2016 event using DInSAR coseismic images, we classify photos of structural damage for the event, and compare their spatial signature.
Prof. Liel’s presentation focused on the risk to structures in Induced Earthquakes. Her research encompasses 3D dynamic structural modeling, seismic hazard and loss assessment, and more!
Ten faculty from the Department of Civil, Environmental and Architectural Engineering at CU Boulder have been awarded a GAANN award to fund eight new PhD students. The project aims to increase the number of graduate students and, eventually, researchers and teachers, who have the multidisciplinary skills to address (i) the country’s deteriorating infrastructure and (ii) the need for upgraded and new transport, water/sanitation, building, and power infrastructure. Applications are now open for students to join our exciting cohort: https://www.colorado.edu/gaann-infrastructure/. We are looking for students with interest in a variety of infrastructure systems and their interdependencies. Other requirements are listed on the linked site.
Zach's research is focused on developing a performance-based framework for analyzing building damage from liquefaction. This includes simplified procedures for estimating the settlement and tilt of shallow foundations. He is currently working on extending the framework to include analysis of densification as a mitigation technique, as well as to connect it to existing regional methods of analyzing liquefaction hazard.
Dustin presented a poster on his research, which aims to benchmark seismic risk predictions from the FEMA P-58 method with empirical earthquake data and other existing risk assessment methodologies such as Hazus. The project has developed a set of over 55,000 FEMA P-58 performance models using the Seismic Performance Prediction Program (SP3) to compare with predictions from Hazus, and found good correlation between P-58 and Hazus for loss predictions of wood light frame structures.
QuakeSmart is a FEMA National Earthquake Hazards Reduction Program (NEHRP) initiative to help businesses in at-risk earthquake communities implement earthquake mitigation actions.
Abbie's talk was entitled “Damage from a Moderate Magnitude Earthquake: What Could Happen in Colorado?” In her talk, she summarized the potential damage from moderate magnitude earthquakes, cost impacts from these events, and potential proactive mitigation techniques.
Recent Ph.D. Graduate Balaji Paramasivam’s paper on the influence of prefabricated vertical drains on soil, foundation and structure response in earthquakes is published in the October edition of the Journal of Geotechnical and Geoenvironmental Engineering. It has been selected as the Editor’s Choice.
Polly Murray, a PhD student at the University of Colorado at Boulder, presented her research on modeling of a ductile reinforced concrete building damaged in the 2016 Kaikoura earthquake to the QuakeCoRE Emerging Researchers Auckland chapter meeting in Auckland, New Zealand. In an effort to understand the performance of ductile RC buildings during seismic events, a 3D nonlinear model was developed to run dynamic analysis. This research aims to compare predicted strength to observed damage, and assess modifications that could improve performance during future seismic events. Laboratory testing of extracted beam-column joints will offer further insight to the extent of building damage.
On August 24th, Rob Chase presented a poster on Damage Accumulation for a Two-Story Wood Frame Building in Sequences of Induced Earthquakes at the Forum for Infrastructure presented by SEG at Oklahoma State University. Rob’s work is focused on examining how potential seismic loss can change in a light-frame wood structure from multiple low magnitude shaking events.
Sarah Welsh-Huggins has been accepted to the AAAS Science & Technology Policy Fellowship (STPF) program, and awarded a placement at the US Agency for International Development in the Office of Food for Peace. The AAAS STPF program aims to connect science with policy and foster a network of science and engineering leaders who understand government and policymaking, and are prepared to develop and execute solutions to address societal challenges.
Sarah will complete her fellowship by supporting the Office of Food for Peace as a technical expert in structural engineering. In her role she will manage the development and implementation of civil infrastructure projects that help to reduce food insecurity in vulnerable populations and build resilience in communities facing chronic poverty and recurring crises like drought.
As an AAAS Science & Technology Policy Fellow, Sarah is among 275 scientists and engineers who will spend a year serving professionally in federal agencies and congressional offices. As highly trained scientists and engineers, the U.S. government benefits from the contributions of STPF fellows, while they learn first-hand about federal policymaking and implementation. The fellowships are operated as part of the American Association for the Advancement of Science (AAAS) mandate to advance science and serve society. The program aims to support evidence-based policymaking by engaging the knowledge and analytical mindset of science and engineering experts, and foster leaders for a strong U.S. science and technology enterprise.
Abbie will be speaking on the EERI Younger Member Committee's webinar on September 17, examining "How induced earthquakes are making us rethink the challenges of earthquake engineering". For more information, or to register, please visit the EERI page.
Zach Bullock's paper, “Probabilistic Models for Residual and Peak Transient Tilt of Mat-Founded Structures on Liquefiable Soils”, has recently been accepted for publication by ASCE's Journal of Geotechnical and Geeoenvironmental Engineering. The paper is co-authored by Zana Karimi, Shideh Dashti, Abbie Liel, Kevin Franke and Keith Porter. This paper is a companion to Zach's probabilistic models for settlement of buildings on liquefiable soils, available online from Geotechnique.
We also provide spreadsheets for users to easily implement these models.
Balaji successfully defended his doctoral dissertation entitled: "Influence of traditional and innovative liquefaction mitigation strategies on the performance fo soil-structure systems, considering soil heterogeneity". Congratulaions, Balaji! We will post his dissertation here when the final version is available.
Casie Venable presented her work entitled "BUILT BACK BETTER? AN ANALYSIS OF PERCEIVED PERFORMANCE OF POST-DISASTER HOUSING" at the Engineering Projects and Organizations Conference in Croatia in June, 2018.
Current and past members of our group were well-represented at the 11NCEE, held in LA in June 2018.
Papers presented include:
EFFICIENCY, SUFFICIENCY, AND PREDICTABILITY OF INTENSITY MEASURES FOR PREDICTING THE CONSEQUENCES OF LIQUEFACTION ON BUILDINGS (work of Zach Bullock and others)
DAMAGE ACCUMULATION FOR A TWO-STORY WOOD FRAME BUILDING IN SEQUENCES OF INDUCED EARTHQUAKES (work of Robert Chase and others)
SEISMIC PERFORMANCE ASSESSMENT OF HSR BRIDGES THROUGH STRUCTURAL SIMULATION AND TESTING (work of Mohammad Salehi and others)
QUANTIFYING IMPROVEMENTS IN SEISMIC PERFORMANCE POSSIBLE THROUGH RETROFIT OF RC FRAMES (work of Cody Harrington and others)
TORSIONAL IRREGULARITY AS A COLLAPSE INDICATOR FOR OLDER CONCRETE BUILDINGS (work of Travis Marcilla and others)
We were also happy to support the efforts of the CU undergraduate seismic design team.
Zach Bullock has produced two models relevant to liquefaction consequences. One predicts settlements of shallow-founded structures, considering soil, foundation and structural properties. The other predicts tilt (or permanent rotation) of mat-founded structures. Both models are fully probabilistic.
Check out these resources to get started:
1) the manuscript describing the settlement model ("A physics-informed semi-empirical probabilistic model for the settlement of shallow-founded structures on liquefiable ground"), published in Geotechnique
2) the manuscript describing the tilt model ("Probabilistic Models for Residual and Peak Transient Tilt of Mat-Founded Structures on Liquefiable Soils"), recently accepted by the Journal of Geotechnical and Geoenvironmental Engineering
3) a spreadsheet for implementing both settlement and tilt models.
Details about the numerical simulations of soil-foundation-structure interaction on liquefiable ground that partially underlay the models is in a paper available from Soil Dynamics and Earthquake Engineering.
I have had amazing mentors in my life. One of the most influential - Professor David Billington.
Check out this story (https://www.princeton.edu/news/2018/04/05/david-billington-scholar-structural-art-dies-90) about his legacy.