ABSTRACT

ABSTRACT: A large number of structures in Adapazari, Turkey collapsed or were heavily damaged due to strong ground shaking or ground softening resulting from the August 17, 1999 Kocaeli earthquake. The softening of shallow silt deposits led to relative vertical displacement of buildings into the ground, building tilt, lateral translation of buildings, and broken underground utilities. Sediment ejecta were observed at some locations but not all. Following the earthquake, systematic surveys of building damage and ground failure were completed, which were followed by comprehensive subsurface investigations. These investigations are summarized, and the different types of foundation failures observed in Adapazari are described. The building survey data show the interdependence of structural damage with ground failure. Areas within the city with significant ground failure commonly had relatively greater amounts of buildings with significant structural damage. The mechanisms that might have led to the observed building performance are described.