A.A. Dumanoglu

Comparison of asynchronous and stochastic dynamic responses of a cable-stayed bridge

In this paper, asynchronous and stochastic dynamic analyses of a cable-stayed bridge are carried out using the finite element method. The Jindo Bridge, constructed in South Korea, is chosen as a numerical example. In the asynchronous dynamic analysis, various wave velocities are used for the travelling ground motion. Displacements and internal effects are obtained using both methods, and compared with each other. It is observed that the velocity of the ground motion greatly influences the response of the Bridge.

Dynamic investigation of a suspension footbridge

Abstract This paper describes the analytical and experimental investigation of a 50 m span pedestrian suspension footbridge in Central Wales, UK. In the analytical study modelling of the three-dimensional structure determined vibration modes involving deck, towers and cables. The prototype testing employed hammer (impact) testing and excitation by pedestrians to determine the corresponding measured modes. The testing showed that adequate descriptions of the vibration characteristic of flexible structures can be obtained without artificial forcing but that appropriate instrumentation should be used. The validated analysis showed that the concrete panelling in the bridge and other structural details have a significant effect on stiffness and the testing demonstrated the susceptibility of this lightly damped structure to pedestrian-induced vibration.

Stochastic seismic response of Keban dam by the finite element method

Abstract In this study, stochastic seismic response of a rock-fill dam is investigated by finite element method. The Keban dam constructed in Elazig, Turkey is chosen as a numerical example. The interaction of the rock-fill dam with the reservoir is neglected, but not the foundation rock. The properties of the dam materials were taken from the dam project and assumed to be linearly elastic, homogenous and isotropic in the analysis. A stationary and ergodicity assumption are is made for stochastic seismic analysis. The E–W component of the Erzincan Earthquake recorded on March 13, 1992, Erzincan, Turkey is chosen as a ground motion since it occurred nearby the dam site. The component considered is applied to the dam in the horizontal direction. The seismic response of the Keban dam subjected to the Erzincan Earthquake is also obtained by the deterministic method. The results obtained from stochastic and deterministic analysis are compared to each other. It is seen that the results obtained from the stochastic analysis are smaller than those from the deterministic analysis.

DYNAMIC RESPONSE OF ROCK-FILL DAMS TO ASYNCHRONOUS GROUND MOTION

In this study, dynamic response of rock-fill dams to asynchronous ground motion is investigated. The Keban Dam, constructed in Elazi˘ g, Turkey, is chosen as a numerical example. In the asynchronous dynamic analysis, wave velocities of 500 m/s, 1000 m/s, 2000 m/s and infinite are used for the travelling ground motion. Stresses are obtained for the wave velocities, and compared with each other. It is observed that the propagation velocity of the ground motion greatly influences the response of the rock-fill dam.