A fracture critical bridge is a bridge or similar span that is vulnerable to collapse of one or more spans as a result of the failure in tension of a single element. While a fracture critical design is not considered unsafe, it is subject to special inspection requirements that focus on the tension elements of its structure.[1]
For a bridge to be defined as fracture critical:
While members subject to compressive stress may also fail catastrophically, they typically do not fail from crack initiation.[2]
Examples of bridge designs that would typically be considered fracture critical are:
The designation and inspection protocols for fracture critical bridges were developed following the failure of an eyebar at the Silver Bridge at Point Pleasant, West Virginia, which precipitated the bridge's collapse into the Ohio River in 1967, resulting in 46 deaths. The disaster resulted in the establishment of the National Bridge Inventory, using the National Bridge Inspection Standards (NBIS) (CFR Title 23, Part 650).[3]
In May 2022 new NBIS guidance established additional terminology to describe new forms of redundancy. These are:
| Structural types |
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| Lists of bridges by type | ||
| Lists of bridges by size | ||
| Additional lists | ||
| Related | ||
