Capacity Vulnerability Analysis For Traffic Network And Algorithm Improvement Based On Earthquake Influence

The destruction of a bridge can cause the relevant road sections unusable,resulting in partial or total traffic network paralysis.So,the control of post-earthquake road network capacity is very important in actual disaster relief and transportation work.This paper proposes a program for calculating the capacity reliability of the postearthquake network,based on the capacity vulnerability of traffic network after earthquake,using MATLAB.It also can be used to calculate the probability that the post-earthquake traffic network can meet the required traffic demand.This program is verified by the Yalu highway network in Sichuan.The results can provide some suggestions for the related traffic network management and decision-making department in the earthquake relief work.First,to analyze the vulnerability of the bridge after the earthquake.The seismic hazard analysis is carried out,then the model of bridge pier is simplified,the nonlinear dynamic time history analysis is carried out,and the vulnerability index of the pier is specified,and the input data of the reliability calculation program of the traffic network capacity after the earthquake is obtained,which is the theoretical vulnerability curve of the bridge node.Then,the post-earthquake capacity of each bridge node is estimated by the obtained failure probability,according to the related literature methods.The calculation program of the capacity reliability of the traffic network is compiled based on the multi state ORDERM sorting,the maximum flow of the network and the network maximum flow estimation algorithm,using MTALAB.Finally,because of the long calculation time and poor calculation precision based on the ORDERM algorithm,the capacity reliability algorithm is also improved,which is called Target-Orderm algorithm(adding the K shortest path).Comparing two algorithms,the difference between the two algorithms in accuracy and running time is obtained.Then the improved Target-Orderm algorithm is used to calculate the changes of the reliability of the traffic network capacity under different recurrence periods and different traffic requirements,to check whether the change law is in line with the reality,to a certain extent,to verify the correctness of the reliability calculation program of the traffic network capacity after the earthquake.