ASCE Seattle Section Geotechnical Group/G-I Chapter
March Meeting
Wednesday, March 22, 2023 at 5:30pm Pacific – Online

Topic: Geotechnical Problems Caused by the 2023 Kahramanmaras Earthquakes

Zoom Link:  https://us06web.zoom.us/j/83796896252?pwd=MFlNZVZjTkppSXJiWTBybkYwUDhvQT09

Speakers:  Ozgun Alp Numanoglu, PhD¹, Tugce Baser, PhD², and Serhat Erinmez³

Moment magnitudes of 7.7 and 7.6 earthquakes struck Türkiye and Syria on February 6, 2023, within 9 hours. Two events and aftershocks impacted several provinces in southeast of Türkiye. The authors performed a reconnaissance to document observations and collect perishable data in the region immediately after the earthquakes. This presentation focuses on the preliminary investigations on the geotechnical aspects including earthquake-induced liquefaction manifestations, settlements, slope, and earth dam deformation/instabilities. Iskenderun experienced widespread liquefaction manifested with sand boils and ejecta on the surface. The settlements were observed both in near-free-field conditions and under the structures including the public dock of Iskenderun. A soil ejecta and significant settlements were observed around a multi-story building and a mosque built on a reclamation area. The settlements were between 5 and 30 cm under the multistory buildings, whereas settlements at the public dock reached at 150 cm. These settlements were also cross-checked with satellite images. The earthquakes triggered several landslides and dam deformations. A significant landslide occurred in Altunozu at a 15 to 30 degree-slope separating an olive farm with a large crack having a thickness and depth larger than 50 meters and 20 meters respectively. Another two meters-wide crack, running parallel to the main crack, was noted several hundred meters away. Single family homes trapped within the cracks experienced up to 55 cm displacements. The reconnaissance highlights the necessity of 1) investigation required for the widespread liquefaction occurred in Iskenderun; 2) monitoring and back-analysis of the earth dams that performed well and those performed poorly during the earthquake; and 3) monitoring of the slope instability in Altinozu.

1. Schnabel Engineering LLC (Speaker)
2. University of Illinois at Urbana-Champaign (Co-Speaker)
3. SiteEye Inc.

Speaker Bios:

Ozgun Numanoglu is a Project Engineer with Schnabel’s Seattle Geotechnical Team. He has three years of consulting experience in geotechnical and earthquake engineering. Ozgun specializes in dynamic characterization and constitutive modeling of soils, and numerical modeling and analysis of seismic ground response and soil-structure interaction. He has worked on a variety of large infrastructure and land development projects across USA and the world including New Zealand, Philippines, and Australia. Ozgun holds a Bachelor of Science and Bachelor of Arts degrees from Civil Engineering and Business Administration departments of Middle East Technical University, Turkey. He also holds M.Sc. and PhD degrees in Civil and Environmental Engineering obtained from the University of Illinois at Urbana Champaign. His area of PhD research and development was focused on three-dimensional constitutive modeling of cyclic response of sands, and numerical modeling and simulation of seismic settlements in dense sands.

Dr. Numanoglu is originally from Adana which was one of the eleven cities impacted by the recent series of earthquakes stroke Southern Turkey.

Dr. Tugce Baser is an Assistant Professor in the Department of Civil and Environmental Engineering at the University of Illinois Urbana-Champaign, specializing in Geotechnical Engineering and Geomechanics. Her research interests include unsaturated soil mechanics, energy geotechnics, and climate change related geotechnics especially in cold regions. Over the years, Dr. Baser has been awarded honors by international institutions and invited as a keynote speaker. She is the recipient of ISSMGE Bright Spark Lecturer Award in 2019; AFOSR Young Investigator and Department of Defense Instrumentation awards in 2021; and Department of Defense Instrumentation award in 2023. She received her PhD degree from University of California San Diego in 2017. Dr. Baser is a member of ISSMGE and ASCE, where she is actively engaged with the student, professional, and diversity development.

Dr. Baser is originally from Adana which was one of the eleven cities impacted by the recent series of earthquakes stroke Southern Turkey.