Vulnerability Analysis Of High-speed Railway System Under Typhoon Disasters In China

A high-speed railway(HSR)system is composed of high-speed rails and high-speed trains.It has the advantages of high speed,safety,high cost-performance ratio,large transfer capacity and so on.The high-speed railway system reduces the travel time between regions and affects their accessibility.Evaluating the impact of the high-speed railway system on regional accessibility is an initial step for improving and plan the high-speed railway system.China is seriously affected by typhoons,which endangers the operation of its high-speed railway system.The typhoon named Mangkhut,which landed in China in September 2018,caused more than 15% of the high-speed trains out of operation,seriously affecting those passengers intending to take these cancelled trains.Analyzing the vulnerability of the Chinese high-speed railway system against typhoon disasters is crucially important for better protect and plan it.This thesis first studies the accessibility of the high-speed railway system in China based on the high-speed train schedule timetable,and then analyzes its vulnerability against the typhoon disasters by using the historical typhoon disasters and those related train outage data.The main contributions of this thesis are presented as follows: First,the fragility models of the components in the Chinese high-speed railway system under typhoons are established;Second,considering high-speed trains' schedule timetable,the accessibility metric and its calculation method are introduced,and then the accessibilities of high-speed railway stations are analyzed;Third,the vulnerability of the Chinese high-speed railway system against the localized attack and the typhoon disasters have been compared and analyzed.Finally,according to the historical data of typhoons,the vulnerability of the high-speed railway system against typhoon disasters is analyzed.Results show that:(1)High-speed railway stations with high accessibilities are mainly distributed around the Beijing-Tianjin-Hebei region,the Yangtze River Delta region and the Pearl River Delta region,and the high accessibilities of those stations near the Beijing-Tianjin-Hebei region also bring the large accessibilities of those high-speed railway stations from Zhengzhou to Shijiazhuang.The Urumqi-Lanzhou line and the Erdos-Hohhot line need to be improved to enhance the accessibilities of those high-speed railway stations along the line.(2)The vulnerability of the high-speed railway system caused by the Typhoon Mangkhut on September 16 is 6.8 times the system vulnerability on September 17.(3)The high-speed railway components in Taiwan and Hainan were seriously affected by the typhoons,followed by those stations along the lines from Zhanjiang to Zhuhai and from Xiamen to Fuzhou.The high-speed railway stations in the coastal areas are the most vulnerable to the typhoon disasters,and the vulnerabilities of other high-speed stations in Changsha,Wuhan,Nanchang,Guiyang,Chongqing and some other areas decrease with the increase of their distances to the sea.