Fault Tree Analysis of Schoharie Creek Bridge Collapse

Abstract

The United States has witnessed several bridge collapses that have resulted in human fatalities. One such failure was the Schoharie Creek Bridge (1987), which motivated the improvement of bridge management policies and procedures. This paper offers a detailed review of the events that resulted in this bridge failure through the use of fault tree analysis. A fault tree is a graphical depiction of the various failure paths that lead to an undesirable outcome. The tree presented considers a host of catastrophic events ranging from vessel collision to fire. Fault trees also provide quantitative assessment and comparison of different failure mechanisms. The results of this analysis present scour as the source of the collapse of this bridge, which was in reality the root cause. Knowledge of the vulnerabilities particular to a bridge aids in the management of similar bridge types, allowing focus upon critical aspects. Recognition of historical bridge failures offers awareness to current bridge engineers and managers that aids in the decision making that promotes public safety and structure preservation. Lessons learned will help avoid similar catastrophic failures in the future.