Fault-Tree Model of Bridge Element Deterioration Due to Interaction

Abstract

Bridge engineers and bridge inspectors recognize that deterioration of one element influences the deterioration of another. The effect of this phenomenon may be critical if it increases the deterioration rate of the affected elements. The phenomenon is known as element interaction. The consequences of element interaction can help to explain why elements of the same type have varying deterioration rates. No practical model exists for modeling element interaction. This paper presents the use of a fault tree for qualitative and quantitative evaluation of element interaction phenomena. The fault-tree results can be used to better assess the deterioration rate and improve deterioration prediction of an element. An example of the fault-tree model for accelerated deterioration of concrete bridge decks is presented. The fault-tree model is not a deterioration model, but can be used to focus on mitigating accelerated element deterioration by certain maintenance or repair actions. Systematic implementation of the fault-tree approach presented herein must be preceded by field verification.