Determination of bridge health index using analytical hierarchy process

Owners of bridges all over the world are facing the task of maintaining them within limited resources. The allocation of resources among the competing deteriorating bridges is a difficult task. Bridge health indices are used for deciding the priority of bridges for maintenance, and for the allocation of resources. Ascertaining the relative importance of bridge components is a prime requirement in the development of the indices. Based on the available literature and preliminary discussions with experts in this field, the bridge components were grouped into seven categories and a questionnaire was developed. The responses to the questionnaire were used in the analytical hierarchy process for deciding the weights (relative importance) of each bridge component. Consequently, based on the literature review, different condition states were defined, and a quantification of different distress types, corresponding to each of the condition states, was made. The weights and condition states of different bridge components were used to develop a bridge health index. The condition states were obtained using visual inspection, according to the definition. The index can be applied easily by different stakeholders for ranking a number of bridges in a bridge stock for maintenance actions, thereby optimizing resources.