VULNERABILITY ASSESSMENT AND RANKING OF STEEL BRIDGES

Failure of Connecticut's Mianus River bridge in 1983, the New York State Thruway's bridge over the Schoharie Creek in 1987 and the recent failure of the US 51 bridge in Covington, Tennessee, have underscored the importance of inspection, evaluation and maintenance in achieving bridge safety. However, the magnitude and cost of arbitrary bridge safety assurance actions can be prohibitive. Since budgetary restraints limit even safety actions a prioritizing system is needed which can identify the most vulnerable bridges for remedial project work. The system must distinguish between rather benign local failures and catastrophic failures resulting in a significant hazard to the lives of the travelling public which may include total collapse of a bridge or bridge span. This paper presents the essential details of such a system which provides a practical and immediately implementable method of identifying the most vulnerable bridges or spans within a given population. It is being reviewed for inclusion in a comprehensive bridge management program currently being implemented by the New York State Department of Transportation.