Observed Damage Behavior of Earth Dams During the 2023 Kahramanmaraş, Turkey, Earthquakes

Abstract

This study describes and characterizes the damage behaviors of earth dams during the February 6, 2023, earthquakes in Kahramanmara & scedil;, Turkey. The first major earthquake occurred in Pazarc & imath;k (Kahramanmara & scedil;) in the early morning, resulting from strike-slip faulting, with a moment magnitude of M7.7 and a depth of 8.6 km. 9 hours later, a second major earthquake, also associated with strike-slip faulting and located at a shallow depth of 7 km, struck Elbistan, approximately 80 km north of Kahramanmara & scedil;. The affected area, spanning several hundred kilometers, is situated in southeastern Turkey, near Syria. In this region, there are 140 dams constructed for various purposes such as irrigation, drinking water supply, flood control, and electricity generation. Unfortunately, seventeen dams in Turkey and one in Syria sustained damage during these earthquakes. The damaged dams represent various structural types, including zoned earthfill, earth core rockfill, earth core sand gravel, earthfill, and concrete-faced rockfill. Firstly, this study introduces the damaged dams in the region, elucidates the unique characteristics of the February 6, 2023, Kahramanmara & scedil; earthquakes (M7.7 and M7.6), outlines the earthquake-induced damage types observed in earth dams, and presents empirical expressions for assessing the frequencies and crest accelerations specific to earth dams. Subsequently, it evaluates the seismic performance and damage behavior of three selected earth dams-Kartalkaya, Sultansuyu, and Ar & imath;kl & imath;ka & scedil;-during the earthquakes, considering observed damages, frequencies, and crest accelerations in detail. It is worth noting that the acceleration values at the crest levels of the damaged dams were approximately four times greater than those at the dam foundations.