Research On Time-varying Risk Assessment Method And Application Of Road Dangerous Goods Tanker Transportation Based On ALOHA&ArcMAP

In this paper,the transportation risk of tankers for road dangerous goods is analyzed systematically based on the characteristics of the road section,with ammonia,a typical transportation of dangerous goods,as an example for application research.This research can provide theoretical and technical support for guiding emergency hedging after accidents,judging the time-varying risk of dangerous goods transportation,and avoiding high-risk lines for dangerous goods transportation.The research content of this paper are as follows:(1)The occurrence law of accidents is explored,the characteristics of time,space and accident form are mastered,and the accident occurrence mechanism is analyzed through statistical analysis of 562 road dangerous goods tanker transport accidents.(2)The influence of environmental factors on the diffusion scope of leakage is explored by visualizing the impact area of dangerous cargo leakage using ALOHA simulation and ArcMAP layer matching,which provides a basis for guiding the emergency evacuation of periphery personnel after the leakage accident.(3)A time-varying risk assessment model based on exposed population and environment sensitive areas is proposed based on the changing law of road traffic volume and the travel law of people along the road.In this model,four kinds of correction coefficients of traffic accident probability,including road inherent characteristics,weather conditions,transportation time and road traffic environment,are introduced.considering the probability of accidents and the consequences of accidents,and the compensation coefficient is added to reflect the mitigation effect of emergency rescue on accident consequences.(4)The.method for determining the scope of the accident is studied.For the determination of the scope of impact of a non-specific accident scenario,the influence of the wind direction frequency on the diffusion range is considered,introducing the pollution coefficient.And an offset rectangular model to determine the impact area of the accident is proposed.For the leakage accident of a specific accident scenario,based on the accident point-based consequence assessment method,the equivalent impact radius is determined to determine the risk assessment scope.Finally,the practicality and effectiveness of the model and method are verified by case analysis.Taking the A city road network as an example,the time-varying risk of each road section of the road network is calculated by setting an accident scenario.The calculation model of the section transportation cost under time-varying conditions is proposed,and the dual-objective path selection model is established based on the BPR function.The improved depth-first search(DFS)and fast non-dominated sorting algorithm are programmed in python to solve the model.The Pareto non-dominated solution of the transportation route is obtained based on the principle of avoiding high-risk transportation routes.Decision makers can select appropriate transportation routes according to different preferences based on time-varying features.