Life-cycle thinking-based decision support framework for multispan simply supported bridges under typhoon-induced wave, current and surge conditions

Coastal bridges usually suffer from wave, current, and storm surge hazards simultaneously under typhoons. Comprehensive mitigation measures can reduce the structural failure probability under these hazards but usually lead to a conservative structural design and a significant increase in the project budget. With the recent development of sustainable structural design, the multicriteria decision-making method can assist engineers in incorporating the life-cycle investment and probability of hazards in the design selection. In this paper, a lifecycle thinking-based decision support framework that considers multicriteria trade-offs and sustainable design was proposed for the design of coastal bridges under typhoon-induced wave, current and surge conditions. The simulation of the typhoon-induced wave, current and surge conditions was developed using SWAN + ADCIRC model, joint probability and environmental contours. The multispan simply supported (MSSS) bridge was then used to illustrate the framework. The main findings include that the void slab girder is better than the other girder types in the equal-weighted, risk-averse and pro-economic scenarios for the example bridge, but the change in girder types has a small impact on the economic cost index score. The increase in the girder height can increase the failure probability when deck shifting dominates the superstructure's failure.