Nonlinear Dyn (2009) 58: 655–673 DOI 10.1007/s11071-009-9508-x ORIGINAL PAPER Comparison of near- and far-fault ground motion effect on the nonlinear response of dam–reservoir–foundation systems Alemdar Bayraktar · Ahmet Can Altuni¸ sik · Barı¸ s Sevim · Murat Emre Kartal · Temel Türker · Yasemin Bilici Received: 27 October 2007 / Accepted: 3 April 2009 / Published online: 17 April 2009 © Springer Science+Business Media B.V. 2009 Abstract In this paper, it is aimed to compare the near- and far-fault ground motion effects on the non- linear dynamic response of dams including dam– reservoir–foundation interaction. Two different types of dams, which are concrete arch and concrete faced rockfill dams, are selected to investigate the near- and far-fault ground motion effects on the dam responses. The behavior of reservoir water is taken into account using Lagrangian approach. The Drucker–Prager ma- terial model is employed in nonlinear analyses. Near and far-fault strong ground motion records, which have approximately identical peak ground accelera- A. Bayraktar ( ) · A.C. Altuni¸ sik · B. Sevim · T. Türker · Y. Bilici Department of Civil Engineering, Karadeniz Technical University, 61080, Trabzon, Turkey e-mail: alemdar@ktu.edu.tr A.C. Altuni¸ sik e-mail: ahmetcan8284@hotmail.com B. Sevim e-mail: bsevim18@hotmail.com T. Türker e-mail: temelturker@hotmail.com Y. Bilici e-mail: biliciyasemin@hotmail.com M.E. Kartal Department of Civil Engineering, Zonguldak Karaelmas University, 67100, Zonguldak, Turkey e-mail: murat_emre_kartal@hotmail.com tions, of Loma Prieta (1989) earthquake are selected for the analyses. Displacements, maximum and min- imum principal stresses are determined using the fi- nite element method. The displacements and principal stresses obtained from the analyses of dams subjected to each fault effect are compared with each other. It is clearly seen that there is more seismic demand on displacements and stresses when the dam is subjected to near-fault ground motion. Keywords Concrete arch dam · Concrete faced rockfill dam · Dam–reservoir–foundation interaction · Drucker–Prager model · Far fault ground motion · Finite element method · Near fault ground motion 1 Introduction Near fault ground motions recorded in recent major earthquakes (1999 Taiwan Chi-Chi, 1989 Loma Pri- eta, 1994 US Northridge and 1995 Japan Hyogoken- Nanbu) are characterized by a ground motion with large velocity pulse. It produces high input energy on structures in the beginning of the earthquake. Com- parison of the near-fault strong ground motion veloc- ities with far-fault strong ground motions is shown in Fig. 1. These pulses are strongly influenced by the ori- entation of the fault, the direction of slip on the fault and the location of the recording station relative to the fault which is termed as ‘directivity effect’ due