Operational Risk Assessment System Of Urban Rail Transit In Mountain City And Emergency Main Risk Management Control

This paper focuses on the accident risk and safety issues in mountain city rail transit operation.Funded by the key project of Chongqing science and technology innovation(Chongqing Rail Transit Risk Assessment and Rectification Countermeasures Research),this paper takes the urban rail transit in Chongqing as an example and adopts methods,such as expert evaluation,numerical simulation and fuzzy evaluation analysis to investigate operation risk identification and judgment of mountain urban rail transit,accident risk mechanism and accident occurrence law,mountain urban rail transit operation risk assessment system and risk emergency management and control strategy of major emergencies,so as to lay a theoretical foundation for safety risk management,control and accident prevention of mountain urban rail transit operation.The main contents and conclusions of this work are as follows:(1)Through the statistical analysis of urban rail transit accidents at home and abroad,the main accident types and characteristics of urban rail transit operation at home and abroad are determined,and the occurrence rules of domestic urban rail transit operation accidents and time(year,month,week,day)and location are obtained;Based on the identification and analysis of the characteristics of Mountain Urban Rail Transit and the influencing factors of accident risk,four main risk factors of mountain urban rail transit operation,such as "large passenger flow" passenger stampede,facility and equipment failure,extreme weather and environmental geological disasters,are obtained,and the accident tree of seven main risk events of mountain urban rail transit operation is constructed;From the analysis of the importance of each fault tree structure,combined with the actual risk control conditions and difficulties,it is proposed that the control of four main risk factors is the key way to solve the operation accident risk of mountain city Chongqing rail transit.(2)According to the topographic and geomorphic characteristics of mountain city Chongqing as a mountain city and its rail transit layout characteristics,the risk Genesis conditions and development types of environmental geological disasters of mountain city Chongqing rail transit are defined,the spatial and temporal distribution laws of environmental geological disasters along mountain city Chongqing rail transit are obtained,and the risk factors of environmental geological disasters along mountain city Chongqing rail transit are determined,It lays a foundation for the risk assessment of environmental geological disasters along the rail transit in the mountain city of Chongqing.(3)Aiming at the accident risk of mountain urban rail transit,based on the C4.5algorithm of information gain rate,this paper constructs the decision tree fuzzy analysis model of mountain urban rail transit operation risk,and selects four first-class indicators of personnel risk,equipment and facilities risk,environmental risk and management risk and their corresponding 20 second-class indicators,The fuzzy safety risk assessment index system of rail transit operation in mountainous cities is established;By introducing the concept of Equivalent Infinitesimal in Taylor formula,the decision tree of rail transit risk assessment in mountainous cities is constructed;Taking the mountain city Chongqing Rail Transit Line 1 as an example,the results show that the J value of its operation safety risk level is 3,that is,it is generally at the general safety level.(4)Aiming at the greater safety risk factors of LPF that is likely to lead to passengers trampling accidents in mountainous urban rail transit at peak times,based on the theoretical research of crowd behavior dynamics,the evacuation behavior of people in rail transit stations is described,and a crowd evacuation model which can introduce the cellular automata model considering the path characteristics into the numerical simulation analysis of the emergency evacuation of the LPF during the peak period of the interchange station is proposed.Taking Daping transfer station of Mountainous City urban rail transit as an example,the parameters of the proposed model are set,and the emergency evacuation of LPF during rush hour at Daping transfer station is numerically simulated.The simulation analysis is divided into two conditions:(a)Normal emergency evacuation of pedestrian passageway under the condition of station fire outage and outage.(b)Emergency evacuation when the right passageway of the platform of Line 2 is blocked due to violent terrorist attack or accident.The numerical simulation results under the two conditions show that the predicted maximum passengers during peak hours can be evacuated within 328 s at Daping Station when all pedestrian channels are clear.The emergency evacuation of LPF during rush hour in Daping Transfer Station meets the requirement of 360 s.However,when a pedestrian passage is blocked in the station,there will be a large area of personnel congestion at the middle exit of the platform,and the evacuation time will reach 376 s,exceeding the critical value of 360 s.(5)In order to control the most important and prone failure risk of rail facilities and equipment in mountainous urban rail transit,from the perspective of ensuring the stable performance and operation safety of "hardware" of mountainous Chongqing urban rail transit system,This paper puts forward the reliability centered maintenance mode(RCM)strategy to deal with the failure risk of facilities and equipment,and the formulation of RCM strategy applied to the failure maintenance of subway door system in mountainous Chongqing urban rail transit.The results show that through the formulation of RCM strategy,the maintenance decision is more reliable and the unity of operation safety and economy of rail transit facilities and equipment is realized.(6)According to the main accident risks of mountain city Chongqing rail transit operation,this paper puts forward the emergency evacuation control of LPF during peak hours in mountain cities,the risk control of rail transit facilities and equipment failure in mountain cities,the risk control of rail transit operation under environmental geological disasters and extreme weather conditions in mountain cities Risk management and control strategies such as "two tables and two cards" risk management and control mode for the first-line key posts of rail transit operation in mountainous cities and the construction mode of rail transit safety culture system in mountainous cities.