Evaluating the Economic Interest of Seismic Isolation for Short and Medium Span Bridges Using a Life-Cycle Analysis Approach

Abstract eng:
In several Canadian localities, the seismic hazard has a significant impact on the cost of bridges foundations. In order to mitigate the earthquake effects on the design of bridges, separating the superstructure from its foundations using seismic isolation sometimes proves to be an interesting option. But under which circumstances is seismic isolation attractive from a strictly economic point of view? This project aimed at answering this question while looking a little further than the construction costs, that is, incorporating all incurred costs over a 75 years life-cycle. The “circumstances” were defined with parameters combined in different sets, in order to represent all common bridges likely to be built in Eastern Canada. A parametric study and detailed analysis (NLTHA, POA, MMRSA) allowed for the design of each bridge case. The performance-based design approach and hazard curves from the S6-14 standard were used. From detailed analysis, the construction costs of bridges designed with, and without, isolation devices were estimated. The life-cycle costs were afterward estimated using common techniques given in the literature, but adding the repair costs following the damages caused by the probable earthquakes on the life cycle. To achieve that, fragility curves of selected bridge elements were built, using the IDA technique, and then combined in an innovative manner with the hazard curves of the localities. Life-cycle costs of the bridges were then compared in order to conclude on the bridge cases that will typically have an economic potential for seismic isolation. Orders of magnitude of the expected savings brought by seismic isolation on both the construction costs and the life-cycle costs were developed.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket