A Study Of Multi-effects Influence On Upward Evacuation Speed Models On Deep-seated Underground Transportation Junction

With the rapid progress of urbanization in China,land use in urban core areas is becoming increasingly tense,and urban development presents a three-dimensional development trend.Accompanied by the emergence of high-rise and super-high-rise buildings in the core area of the city,the number of Underground Multi-storey crowded places has gradually increased,for example,the emergence of large underground comprehensive transportation hubs and subway transfer stations in major cities in China.In order to realize its complex building functions,large-scale comprehensive transportation hub and other places with dense personnel are constantly shifting from ground to underground space,and the depth of burial is constantly changing from shallow underground to Underground Multi-storey and Underground Multi-storey to deep burial.The deep underground comprehensive transportation hub is a new thing in recent years,and its emergency evacuation research is also a new research field.Taking Shapingba Comprehensive Transportation Hub Project in Chongqing as an example,the vertical height difference of the underground part is equivalent to 12-storey high-rise buildings,whose maximum burial depth has reached 36.5m.In case of disasters,the lowest-level personnel must climb stairs at least equivalent to 12-storey to reach the ground safety area.Actively carrying out large-scale emergency evacuation and induction research for large-scale comprehensive transportation hub is the need to solve a large number of technical problems in the design and evaluation of evacuation safety for such underground buildings;it is the basis to provide the necessary first-hand basic data for the safety design and evaluation of such buildings and to eliminate the evacuation speed.The evacuation safety risks and hidden dangers brought by the data and prediction model "Zhang Guan Li Dai" and the need to ensure the safety of personnel’s lives are the needs of adapting to the new trend of urbanization process in China and enriching and perfecting the existing theoretical system of personnel evacuation.Up-going evacuation is significantly different from downward and horizontal evacuation: 1)It takes more physical energy than downward and horizontal evacuation of ground buildings;2)the personnel confluence at stairway entrance and the personnel density in stairway section directly affect the evacuation speed;3)the consistency of evacuation direction and smoke movement direction leads to "visibility".(4)Evacuation with luggage increases the evacuation burden,and if people give up their luggage,the evacuation of follow-up personnel will be adversely affected.In this paper,some behaviors and related problems of personnel upward evacuation in deep-buried underground integrated transportation hub are studied by means of modeling and empirical methods.They are:(1)Based on the long-distance upward evacuation experiment of single factor,double factor and multi-factor synergistic action carried out by the research group,basic data are obtained,and comprehensive consideration is given to the deep-buried underground integrated transportation hub.Based on the fact that there are multivariate,anisotropic and time-dependent evacuation in New Zealand,the "fatigue factor","personnel density factor" and "visibility factor" are added to establish a "fine-field cellular automaton evacuation dynamics model".(2)Through calculation and demonstration,the advantages of the "fine field cellular automata upward evacuation dynamics model" have been fully proved.(3)The simulation application research is carried out by using "the precise field cellular automata evacuation dynamics model of comprehensive personnel multidirectionality,anisotropy and time dependence".Experiments and simulations were carried out without considering fatigue(i.e.constant velocity),fatigue,visibility,confluence,fatigue and visibility.The simulation results are basically consistent with the experimental and observed results.The innovation of this paper lies in that,based on the long-distance evacuation experiment of single factor,double factor and multi-factor synergistic action carried out by the research group and the basic data obtained,the theoretical modeling process is based on the fact that there are multiphase,anisotropy and time correlation in the evacuation of deep underground comprehensive transportation hub.Adding "fatigue factor","personnel density factor" and "visibility factor" to adjust the power and probability of people moving forward or turning to simulate the changing law of evacuation speed in the process of evacuation,so as to improve the accuracy and application scope of fine field model in the field of evacuation simulation.In addition,it is worth mentioning that compared with the cellular automata model of fine grids used to solve conflict problems in previous studies,the model proposed in this paper has innovative advantages in the following aspects: 1.flexibility and scalability.(2)Higher dimensional accuracy.(3)Wider speed range.(4)Relatively low computational consumption.(5)Detailed ways of conflict resolution.