Study On The Method Of Lightning Disaster Risk Assessment For Railway Integrated Transportation Hub

Because railway integrated transportation hub is characterized by large scale of construction, high concentration of population and high electromagnetic sensitivity, lightning protection is of great responsibility. However, there is still a lack of the lightning disaster risk assessment method for this kind of hub. In the paper, a method of the lightning disaster risk assessment for railway integrated transportation hubs has been proposed; furthermore this method has been applied to the integrated transportation hub of Changchun West Railway Station based on the characteristics of lightning disaster and activity in Jilin Province. The main findings are as follows:Firstly, a method of the lightning disaster risk assessment for railway integrated transportation hubs was proposed based on Analytic Hierarchy Process (AHP) combined with comprehensive weighted method. Ten risk impact factors are recognized and defined as sub-criterion layer:county lightning vulnerability, terrain, soil electrical resistivity, lightning intensity, lighting density, rate of lightning shielding failure, area personnel lightning strike vulnerability, economic lightning strike vulnerability of buildings, type of lightning protection of buildings, and lightning protection level of electronic information systems in buildings. In the same time, the value of each factor was established. The methods for assessment of the probability of physical damage of buildings caused by lightning strike (PB), the probability of inner system failure caused by buildings strike by lighting (Pc) and regional lightning screening techniques were presented especially.Secondly, the lightning disaster risk descends from central Jilin Province to its surroundings, and severe-risk areas are mainly located at prefecture-level city area in central and southern Jilin Province, while high-risk areas are mainly located at the counties with relatively high economic development level in central and southern Jilin Province; medium-risk areas and low-risk areas are mainly concentrated in the eastern plains and western mountain areas, respectively. The average flash density is3.0times-km-2·a-1in Jilin province, which is slightly higher in central and southern Jilin province and lower in eastern and western Jilin province. The amplitude of lightning current is mostly between20to40kA. Lightning density average is of3.1times-km-2-a-1in Changchun city, which is slightly higher than the average for whole Jilin province. The lightning disaster vulnerability of Changchun is0.682, which is located in high-risk areas of lightning disaster.Thirdly, the lightning disaster risk of Changchun West Railway Station railway integrated transportation hub is at a low level. The three risk impact factors with highest level for the hub are area lightning density, county lightning disaster vulnerability, and area personnel lightning strike vulnerability, respectively. The risk of the life loss inside the building and the economic loss are within the range of allowable values, however, the risk of the life loss in-6.5m bus parking layer, and-6.5m and-12m distribution Plaza layer are higher than other areas, which indicates that the further improvements of the existing lightning protection devices are required. The result shows that the method of lightning disaster risk assessment for the railway integrated transportation hub proposed in this paper can provide an effective calculation on lightning strike risk that may exist in the railway integrated transportation hubs, and this method is scientific and rational, which can provide a useful help to further improve the existing lightning protection measures.