Optimal allocation of resources for increasing the seismic reliability of lifelines

A given amount of monetary resources can be allocated in an optimal way to increase the seismic reliability of a network by upgrading its critical elements. In this optimization, several objective functions can be selected, e.g., the reliability of the network, the time-efficiency of the interventions, the out-of-service time of the network after an earthquake. By way of example, the corresponding three optimized distributions of the upgrading interventions on the five bridges inserted in a given highway network are obtained and discussed in this paper.