Dams in the wake-up call of the 2023 Türkiye earthquake sequence: Insights from observed damages, risk assessment, and monitoring

Abstract

On February 6, 2023, Türkiye experienced a significant earthquake with a magnitude of Mw 7.811Note these values are based on initial assessment by USGS. AFAD reported differently., followed by four additional earthquakes throughout the day, measuring Mw 5.8 and above, including one with a Mw 7.5. As a result, over 100 dams in the region experienced low to high seismic loads. The impact of these seismic events resulted in a range of damages to dams, varying from light to severe. The authors participated in several post-earthquake reconnaissance missions to collect perishable data regarding the damage. This paper is three-fold: First, it explores the seismic performance and observed damage in 17 dams (majority embankments) based on data collected from the field. During the seismic activity, embankment dams underwent failure modes such as strength deterioration, yielding, settlement, tension crack formation, as well as sliding along planar or circular surfaces. Second, the paper offers an updated seismic risk analysis for ten selective damaged dams in the regions. Total risk factors are quantified using two different methods. The results show that the majority of the studied dams are classified as high and very high-risk dams. Third, the paper evaluates 11 other dams in the region that were equipped with sensors for monitoring the ground motions. The recorded acceleration at the crest and the abutment are further used to investigate the amount of amplification based on transfer functions. These recordings will be crucial for subsequent model calibration and system identification. Overall, the paper’s objective is to contribute to sharing post-earthquake reconnaissance mission information and to establish the groundwork for in-depth numerical analyses and quantitative risk assessments of dams located in seismically vulnerable areas.