Study On Uncertainty Of Occupant Safety Egress Under Emergency State In Subway

The complexity of subway structure and the randomness of the conduct of members determine the uncertain during the subway evacuation in the state of emergency. The safety egress time and the passenger flow of each outlet are the important indicator of evaluating egress results, which contains uncertainties. Uncertainties were often ignored or calculated using conservative safety factor method. The short of quantitative methods of uncertainties makes deviation of calculated results and the actual results of egress. Effectively accessing and quantifying parameter uncertainties during subway egress system design and evaluation deserve further exploration.The article analyzes the subway station occupant egress from subjective and objective aspects based on finishing the occupant egress theory and clarified the safety egress time in the relevant specifications, which laid the theoretical basis for building the simulation model and established analytical standards for the analysis results of occupant egress in this article. According to the characteristics of metro station egress, the article analyzes the subway egress uncertainties from the vague uncertainty, the random uncertainty, spatial uncertainty and timing uncertainty four aspects and established the system of uncertainty analysis, which provided a theoretical basis for the uncertainty analysis of actual case.Based on the uncertainty parameters and probability distribution in subway egress, a large number of input samples are obtained by the Latin Hypercube Sampling Method of Monte Carlo. The outputs are calculated by the Pathfinder simulation, which contributes to preliminary determine sensitivity between factors by some statistical methods. The article quantitative analyzes the impact of uncertainties on the results of the safety egress based on the single factor sensitivity analysis method. The factors' sensitivity are discriminated by comparing the fluctuations range of egress time. Finally, the analysis result shows the most sensitive factor to the subway station egress during security state and the reliability of the whole station safety egress, which provides instruction for the subway station operation management and occupant safety egress.