ANALYSIS AND OPTIMIZATION OF POST-EARTHQUAKE RESTORATION PRIORITY OF BRIDGE NETWORK UPON FRAGMENTATION

In order to study the seismic restoration of regional bridges, aiming at the post-earthquake repair priority of urban bridge networks, a network fragmentation partitioning method (FaDPa) based on traffic density was introduced, and a dual toughness index considering recovery and economy was proposed, and a phased optimization method was introduced according to the time period characteristics of short-term rescue and long-term restoration after earthquake, especially in the long-term restoration stage based on different restoration needs. The fragmentation theory was applied to the rescue and relief stage and the long-term repair stage respectively. The former optimized the rescue order with recovery toughness and time as the target, while the latter optimized the repair order with comprehensive toughness, debris recovery and time. The result shows that the fragmentation theory proposed makes different divisions based on density for the seismic damage degree of different repair stages of the bridge network. The staged repair work on this basis has improved its comprehensive toughness by 52.3% in the process of emergency rescue and disaster relief. Under the premise of not affecting the toughness optimization in the long-term repair process, the fragmentation resilience is increased, and its functional level is increased by 20.3%. In the repair optimization stage, the dual toughness index considering different repair directions and the optimization theory of time-phase processing can be flexibly adjusted according to the needs of decision makers, so that it can adapt to different repair environments, and the repair results considering fragmentation theory supplement the reliability of repair from different dimensions.