Risk index and risk minimization for bridges

The age and the increase in the traffic volume lead to the deterioration of bridge condition and at the same time increasing the risk to bridges and the users. The federal highway agencies in the United States face a big challenge in maintaining the bridges in good health because of the lack of sufficient funds and resources. Current bridge managements are using the cost as a main factor for determining the maintenance strategies which is very imprecise. Bridge management strategies or methodologies which are based on the risk factor of a bridge are needed to utilize the limited resources at its best. This thesis paper proposes a systematic approach for assessing risk calculating risk index of a bridge based on the condition of their elements and importance of the element which helps to prioritize at the bridge-level. At network level an algorithmic methodology called 0/1 Knapsack Problem (KP) has been implemented to yield an optimal selection of candidates from the network when subjected to budget constrain. A framework has been presented with data available obtained from Texas Department of Transportation (TxDOT). The recommended procedure helps the decision maker to decide his priority structure in a more practical way and also helps in prioritizing at the bridge-level and achieving an optimal solution at the network-level which minimizes the risk in the overall bridge network in a limited funding.