Upgrading Seismic Reliability of Large Scale Lifeline Networks

ABSTRACT We have developed an algorithm with which to assess the seismic reliability of large scale lifeline networks that is based on the concept of the critical distance to a fault; i.e, the shortest distance to a fault that causes failure of components for a given earthquake magnitude. The enumeration of paths in the network was found to be at most 2n 2 -2n+2 for a network with n components. Using this developed algorithm we propose three measures for specifying critical components in lifeline networks. For each measure the sequence that strengthens each component is defined for the upgrading of the seismic reliability of the total system. Lifeline components are assumed to fail because of ground shaking. The seismic environment of a lifeline is defined by the fault rupture model through the relation of the seismic moment to the rupture area. Calculation of the seismic reliability of an example network and evaluation of a component's importance show that this new technique can be used with large networks.