Geometrically nonlinear deterministic and stochastic analyses of suspension bridges to multiple support sesimic excitations

SUMMARY Geometrically Nonlinear Deterministic and Stochastic Analyses of Suspension Bridges to Multiple Support Seismic Excitations In this study, deterministic and stochastic responses of suspension bridges to multiple support seismic excitations are investigated by considering geometrically nonlinear behavior. S16E component of Pacoima Dam record of 1971 San Fernando earthquake and east- west component of 1992 Erzincan earthquake are used as ground motions in the deterministic analyses. In the stochastic analyses filtered white noise model modified by Clough and Penzien is considered as a ground motion. The ground motion model used for the multiple support seismic excitations includes the effects of incoherence, wave passage, and site response. Because of the complex nature of earth crust, the multiple support seismic excitations should be taken into account in the deterministic and stochastic analyses of long span structures like suspension bridges. The thesis prepared with this scope includes the following chapters. In the first chapter, general information, the importance of the matter, previous studies about the subject are given. The formulations of deterministic and stochastic analyses are also presented in this chapter. In the second chapter, the ground motion model used in the stochastic analyses is given. Besides, the analytical model of Bosporus Suspension Bridge chosen as an example is occurred and the frequencies and mode shapes obtained from modal analysis of the bridge are also shown. In the third chapter, response values obtained from deterministic and stochastic analyses of suspension bridge to multiple support seismic excitations are discussed. As the results and recommendations obtained from the analyses are given in chapter four, the references are presented in the next chapter. As a conclusion it can be observed that multiple support seismic excitations have significant effects on suspension bridges. So, these effects should be considered in the analyses of long span structural systems like suspension bridges. Keywords: Deterministic Analysis, Stochastic Analysis, Suspension Bridge, Geometrically Nonlinear Behavior, Dynamic Response Component, Pseudo- Static Response Component, Covariance Function, Power Spectral Density Function, Filtered White Noise, Multiple Support Seismic Excitation, Incoherence Effect, Wave-Passage Effect, Site-Response Effect. VII