Uzak fay sismik bölgelerinde köprülerin performansa dayalı sismik tasarımı için deprem yükü azaltma katsayılarının geliştirilmesi

In this thesis, a methodology to develop strength reduction factors for performance-based seismic design of bridges in far-fault seismic regions is presented. The presented methodology is mainly based on performing linear 5%-damped response spectrum analyses (RSA) and nonlinear time history analyses (NTHA) of bridge piers modeled as single degree of freedom (SDOF) systems. Bridge piers of both circular and rectangular sections are analyzed for wide ranges of various design parameters considering several substructure-superstructure connections. Subsequently, a set of strength reduction factor (R-factor) equations derived by performing parametric linear regression analyses on the data resulted from the conducted structural analyses is proposed. The proposed R-factor equations are formulated in terms of the design parameters that significantly affect R-factor, and the maximum displacement ductility obtained from the NTHA considering various failure modes such as shear, shear-flexural, and flexural failure modes. Moreover, other equations to estimate the yield curvature, ultimate curvature, and yield moment capacities of bridge piers are proposed. Such equations that could be used to estimate the design displacement and flexural strength capacity of piers in the performance-based seismic design of bridges. Based on the derived equations in this thesis, a new performance-based seismic design procedure for bridge structures that mainly depends on R-factor is proposed. Finally, the implementation of the proposed design procedure is explained via design examples of bridge structures.