OPTIMAL ALLOCATION OF RESOURCES IN REDUCTION OF THE SEISMIC RISK OF HIGHWAY NETWORKS

The optimization of preventive upgrading interventions on the bridges of a highway network in an earthquake prone area is tackled. The bridg es are assumed to be the vulnerable elements of the network, whose mai n purpose is to connect two sites. If the probability of collapse of e ach bridge under an earthquake of given intensity is known, the topolo gy of the network allows us to calculate its reliability, i.e., the pr obability of maintaining the connection between the source node and th e destination node. To increase the reliability, preventive upgrading interventions must be designed: the main purpose of this study is to p resent a procedure, based on dynamic programming, which is able to dis tribute the interventions among the bridges so that, for a given total amount of employed resources, the increase in reliability is maximize d. The applicability of the procedure is demonstrated by some complete numerical examples. Alternative choices of the objective function and other further developments are also discussed.