Behaviour of cable-stayed bridge's girder to multi-support excitation

This paper describes the behaviour of the longitudinal and cross girder of cable-stayed bridge due to multi-support excitation. Cable stayed bridges should be analysed by different support accelerations since generally they have long spans. In this research, an 800 m long cable stayed bridge was assessed by giving different support accelerations. The method used is by arranging simulation using structural analysis software. The displacement time histories are obtained by converting the response spectra using MathCAD. The structural responses were then compared to the application of single support excitation. Results show that there is a significant discrepancy between the two analyses. Single support excitation causes lower responses if the ground motion magnitudes are similar to the small magnitude of the multi-support excitation, and it yields to a higher responses if the magnitudes are similar to the greater value of the multi-support excitation.