Study On Evaluation Of Safety Evacuation Acceptance In Underground Stations Of Rail Transit

In recent years,China’s rail transit underground stations have gradually shown a trend of scale,complexity,and depth,and the difficulty of evacuation has increased.How to ensure the safety of personnel has become the focus of station design.Although China has issued a series of subway safety evacuation regulations in recent years,and underground stations have also been designed for evacuation under the regulations,disasters still occur from time to time.Can an underground station designed according to the specification meet the requirements for safe evacuation in an emergency? This is the starting point of this thesis.The study found that the current regulations lack the evaluation of the overall evacuation performance of the station.Second,there is a lack of evacuation acceptance evaluation for the underground station after the completion of the construction,and there is also a lack of consideration for the buried depth of the station.Based on the above reasons,this thesis solves the problem of evaluating the safety evacuation performance of underground stations,finds the factors affecting safety evacuation,and proposes a design strategy for safe evacuation.Therefore,this thesis constructs a comprehensive evaluation system that combines index evaluation and performance-based evacuation design,and uses this system to evaluate the safety evacuation acceptance of underground rail transit stations.First,this thesis sorts out the domestic and foreign safe evacuation theories,research trends,evacuation standards,evaluation,etc.,takes the safe evacuation theory as the theoretical basis of the thesis to establish the overall structure of the thesis,and proposes the idea of a comprehensive evaluation system for underground station safety evacuation acceptance.Second,through questionnaire surveys and field surveys of Chongqing Rail Transit underground stations,the current characteristics of underground stations and the factors that affect station safety evacuation are collected and analyzed.Understand the emergency evacuation behavior of people and their awareness of safe evacuation,and perform descriptive statistics and analysis on the status of safety evacuation in selected case stations,and provide a reference for establishing a set of influencing factors for safe evacuation in underground stations.Third,The Analytic Hierarchy Process(AHP)is used to establish the acceptance index evaluation system.Based on the content of literature research,investigation,and expert interviews,the evaluation factors of the safety evacuation acceptance index are determined in hierarchical categories,and a set of factors affecting safety evacuation of underground stations is established.The target layer is evaluated from the four criterion levels of personnel evacuation factors,evacuation infrastructure,evacuation guarantee system,and organizational management factors,and the weight and factor scoring standards are determined to construct a safe evacuation index evaluation system.The fuzzy comprehensive evaluation method(FCE)is used to evaluate the index factors,and it complete the evaluation model of the acceptance index for the safety evacuation of underground stations.Then,the performance-based evacuation design of underground stations is carried out by computer simulation.The thesis uses Pathfinder software for simulation.Considering the station type and buried depth,four types of stations are selected as typical cases,namely shallow side stations,sub-shallow island stations,sub-deep parallel transfer stations and deep cross transfer stations.Evacuation time,bottleneck phenomenon,density and other key performance indicators were quantitatively studied.Finally,through a comprehensive evaluation system combining the index evaluation method and the performance-based evacuation design,the safety evacuation acceptance evaluation of the selected stations is carried out,and the evacuation strategy and recommendations are put forward according to the evaluation results.Aiming at the common problems of safe evacuation in underground stations,design optimization strategies are proposed from two aspects: evacuation management and evacuation design.In view of the insufficient consideration of the buried depth of the station in the standard,the recommended value of the safe evacuation time to the ground at different depths is proposed.