2025 Volume 25 Issue 1 Pages 1_64-1_77
In recent years, a quantitative evaluation method for anti-catastrophe has been proposed. However, this is still conceptual, and it cannot be said that an evaluation method based on design practices has been established. Therefore, we focus on redundancy, which is one of the performance items of anti-catastrophe, and propose a quantitative evaluation method of redundancy for railway bridges and viaducts. In this method, the structural redundancy is evaluated from both perspectives, “margin” that means the displacement leading to collapse against the design limit displacement and “parallelism” that means the change in the margin when the column member disappears. And the structural analysis confirmed the validity of the method. By using this method, it becomes possible to explicitly consider redundancy in seismic design, diagnosis, reinforcement, etc.