Observed Beam-Column Joint Failures During 17 August 1999 Kocaeli and 12 November 1999 Duzce, Turkey Earthquakes

Abstract

The earthquakes which occurred in Kocaeli (Izmit) and in Duzce affected a wide area in the Marmara region of Turkey, leading to huge loss of life and structural damage. Kocaeli and Duzce and their environs are on the Northern Anatolian Fault Line, and include Turkey’s most earthquake prone areas. Records of past earthquakes in Turkey reveal that numerous earthquakes of Ms≥7.0 occurred in the region. The epicentre of the Kocaeli earthquake, Richter magnitude Ms=7.4, was located at lattitude 40.70° N and longitude 29.91° E, [1]. According to Bogazici University Kandilli Observatory’s Earthquake Research Institute, its focal depth was H=10~15 km and the intensity at the epicentre was Io=X-XI MSK. In terms of the devastation it caused, the 1999 Kocaeli Earthquake was the most serious one to hit a Turkish city, and is the second largest earthquake of the century after the 1939 Erzincan Earthquake. For the same reasons, it is one of the most serious earthquakes to have occurred worldwide. The epicentre of the Duzce earthquake having a magnitude of Ms=7.2, was located at lattitude 40.77° N and longitude 31.15° E. According to the evaluations of USGS, its focal depth was H=10km.