Study on Different Cable Configurations of Cable-Stayed Bridges Using Developed Seismic Risk Assessment

Abstract

Changing the cable configuration in a cable-stayed bridge affects the period and damping of the structure and consequently changes the forces in bridge components, which results in change of their required dimensions. Based on this, it can be concluded that altering the cable configuration will result in a change in seismic risk and construction costs. It is therefore necessary to thoroughly investigate the common configurations in order to select an optimal option. In this paper, as a case study, a cable-stayed bridge is designed with three different configurations to compare dimensions and construction costs relatively. The loss due to probable earthquakes can then be investigated simultaneously with the construction costs using the developed seismic risk assessment (DSRA) process, for each configuration employment. The proposed process is performed based on a financial-comparative (FC) approach and consists of three steps: fragility assessment, loss assessment and cost-loss-benefit (CLB) assessment. Final decision-making is done by proposing benefit ratio (BR) as a profitability measure. Results show that the fan and harp cable configurations are the optimal options for cable-stayed bridges with 260 m and 100 m mid-span, respectively.