Tunnel-form system as an ideal solution for seismic regions: a numerical study based on life-cycle cost analysis

Abstract

The present study focuses on the evaluation of the life-cycle cost of concrete tunnel-form system through an innovative approach. Such life-cycle cost analysis accounts for the roles of different building components in generating injury, fatalities, and downtime. Using such an approach, three component categories, namely structural, acceleration-sensitive non-structural, and displacement-sensitive non-structural elements, were considered. For the 5- and 10-story models examined, the results primarily indicate the high strength and stiffness of the tunnel-form system. Even when adopting moderate ductility provisions for the walls, the mean peak ground acceleration corresponding to slight damage state is approximately 0·6 g. The probability of reaching such damage state under the design-basis earthquake is below 10%. Thus, the requirement for special ductility in tunnel-form system walls appears to be conservative. The results also show that acceleration-sensitive non-structural components exert the greatest effect on the system’s life-cycle cost. Overall, for tunnel-form system, irrespective of building height or the type of damage-causing component (structural or non-structural), the earthquake-induced damage cost is consistently estimated to be less than 1% of the initial construction cost. Based on these findings, selecting tunnel-form system for construction in seismic regions appears to be a favorable strategy for enhancing seismic safety factor while minimizing life-cycle costs.