Study On The Emergency Protection Method Of Road Network Based On The Key Nodes After Earthquake

City road network is the skeleton of a city,also is a key factor that influence city’s development.There are always some nodes and sections that control the whole network;these nodes and sections are the hub and key road in the daily operation;when the disaster strikes the city,these nodes and sections will become lifeline of repairing road and saving people because of the broken of city network,having an important influencing on rescue work.Based on the above analysis,we need to find key nodes and important sections and set emergency materials site to protect them.1、For analysis key nodes and important sections of city network in normal state,this paper refine evaluation index by filtering and establish evaluation index system.This paper also design AHP-Entropy-TOPSIS method to calculate and classify the importance of nodes and sections.And take Tianjin’s city road network as example for analysis and verification.2、Considering the reducing pattern of seismic intensity and the decrease of road and bridge’s traffic function.Choose traffic capacity of the road network as evaluation index.Using reduce or invalid communication function method based on the improved reverse detection method to calculate and classify the importance of nodes and sections after earthquake.Also take Tianjin’s city road network as example for analysis and verification.3、For the purpose of protecting key nodes,this paper establish location choosing model of emergency materials site based on reaching the disaster relief point in the shortest time and p-center problem.Design the model algorithm based on time-weighted shortest path problem and genetic algorithm.Using MATLAB genetic algorithm toolbox to solve the model of Tianjin’s city road network.Determine the location of emergency materials site.