01626651

Component

The New York State Department of Transportation maintains a database of over 428 bridges that have collapsed in the United States between 1992 and 2014. These collapsed bridges are associated with inspection data from the National Bridge Inventory (NBI) dated just prior to collapse. A large portion of the collapsed bridges are classified as structurally deficient by the NBI, and a test of independence yields that structural deficiency is a possible predictor of collapse. Further analysis indicates that bridges with a structural deficiency in the substructure are more prone to collapse than those with a structural deficiency in the deck or the superstructure. The scour critical rating is assessed for hydraulic failure, and a test of independence indicates that the scour critical rating is not a predictor of collapse. The results yield that there is a discrepancy between the scour critical ratings given and the significance of the scour. The majority of collapsed bridges are declared stable for the substructure condition rating and the scour critical rating. The significance of the scour present is more significant than it appears to be at the time of inspection. An analysis of age and collapse indicates there is direct relationship between age and overload-caused collapse. For all of the other causes of collapse, there does not appear to be a relationship between age and collapse. Rather, there is a relationship between the revisions done to the design provisions and the causes of collapse. The revisions to the design provisions in newer bridges have decreased the likelihood of a collapse due to random events such as a collision-caused collapse. Newer bridges are being constructed with more vertical clearance, shorter maximum span, and a shorter structure length. Whereas the design load for the majority of newer bridges is known, less information is known regarding older bridges.

This paper was sponsored by TRB committee AHD30 Standing Committee on Structures Maintenance.

01618707

17-06759

English

16p

2017

Transportation Research Board 96th Annual Meeting

Digital/other

Figures; References; Tables

Bridge substructures; Bridges; Collapse; Data analysis; Design load; Inspection; Scour; Trend (Statistics)

National Bridge Inventory

United States

Bridges and other structures; Highways; Maintenance and Preservation

Transportation Research Board Annual Meeting 2017 Paper #17-06759

TRIS, TRB, ATRI

Dec 8 2016 12:46PM