| The 13th five-year plan for the development and utilization of urban underground space issued by the ministry of housing and urban-rural development in 2016 highlights the huge potential of urban underground space development and utilization.At present,the utilization and development of underground space has presented a diversified,complicated and in-depth development model.In the emergency evacuation process of sudden disasters,the safety and efficiency of ascending stairs evacuation becomes extremely important.According to the research,with the increasing depth of underground development,the change of upward exercise-induced fatigue caused by physical factors of personnel will adversely affect the upward evacuation of the group.At present,there are few basic researches on this aspect in China,and most of them focus on descending evacuation,in design practice,the design standards of ascending stairs refer to descending design.However,the impact of exercise-induced fatigue on evacuation of ascending and descending personnel is quite different.So in an emergency,the Efficiency influence of researchers’ exercise-induced fatigue on the evacuation of ascending stairs in underground buildings is of great significance.Therefore,the survey starts with sports fatigue and works on research of people’s upgoing efficiency of the evacuation operation in the underground space.Firstly,by using literature and field research,the survey summarize the situation and problems as well as the research results that related to people’s upgoing evacuation in underground space.Secondly,according to the research on influences of sports fatigue when people evacuate,the survey picks out the relevant physique factor,and verifies by observation on upgoing evacuation of single people.The results of a real person observation experiment show that there was a significant correlation between the gender and BMI of the physical factors of the personnel and the changes of upward movement fatigue.The change of exerciseinduced fatigue will significantly attenuate the evacuation speed,thus affecting the overall ascending evacuation efficiency.However,there is no significant correlation between weight,height and ascending exercise-induced fatigue;based on this,the relationship between the physical factors related to exercise-induced fatigue(gender,BMI)and the change of ascending speed was further discussed,and the relationship between the upward evacuation speed and the upward height of men and women in different BMI intervals was obtained;finally,a mathematical model of ascending velocity changing with ascending height was built by fitting with Matlab and Origin mathematical platform.The verification provides quantitative analysis for velocity change of evacuation of the individual in later experiment of group simulation upgoing evacuation.In addition,combined with the fatigue evaluation of subjective sports of men and women after the experiment and the change analysis of the attenuation of objective evacuation speed of men and women,it is concluded that the significant upward height interval of the influence of male sports fatigue on speed change may be concentrated in 25-33.75 m,while the female may be concentrated in 15-30 m.In these intervals,the evacuation speed of personnel declines the fastest and has the most obvious impact on the upward evacuation efficiency of individuals.The influences of sports fatigue on efficiency of group evacuation,Secondly,the research method of Anylogic simulation is adopted to carry out the simulation experiment on the group ascending evacuation of the middle(-30~0m)and deep(-60m~0m)underground layers respectively for the representative double running stairs,multiple running straight stairs and the three running stairs in the observation experiment.The experimental results of group evacuation in the middle(-30~0)and deep(-60~0m)scenarios indicate that in the three forms of stair ascending evacuation,the location of crowd congestion caused by exercise-induced fatigue is not consistent.Compared with the experimental results,the overall congestion caused by upward movement fatigue is more obvious in the upward 60 m than the upward 30 m.When the group goes up to the height range of 27.3-35.25 m,all three kinds of stairs show obvious congestion.This may be the height range in which the fatigue response to continuous upward movement is strongest.It is easy to cause crowd congestion in this interval,which has adverse effects on upward evacuation.Therefore,it is very important to set corresponding buffer space in this height range to ease the congestion.Finally,based on the above experimental conclusions and combined with the actual cases of commercial and subway buildings with different underground depths,the optimal design strategy of ascending evacuation stairs covering shallow,middle and deep underground buildings is proposed.Specifically,it includes in different underground depth ranges,the three aspects of the selection of the form of architectural evacuation stairs,the adjustment of the design parameters of the stairs based on the impact of movement fatigue,and the design of the refuge buffer space of the middle and deep underground ascending stairs.The research conclusion is expected to provide reference for the design of upward evacuation stairs of underground buildings in the future. |
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