Experimental Study On Walking Speed On The Staircase In Different Visibility Conditions

Due to the closure and particularity of underground multi-storey buildings, people must be with the help of emergency lighting to show them a way in the upstream evacuation process, which significantly differs from the downstream evacuation with the natural lighting in the above-ground buildings. Carrying out the research of the influence of visibility to evacuation speed in staircase, and obtaining evacuation speed value, evacuation behavior characteristics and influence factors in different visibility conditions, are effective measures to supplement evacuation design of this kind of buildings.Based on the summary of previous staircase evacuation researches, this paper conducts a systematic study of normal conditions, lighting failure conditions and upstream and downstream evacuation time in long distance stairs, evacuation speed, influence factors and evacuees’behavior characteristics of wearing eye-patch of 27% and 16% transmissivity conditions. Also, the experiment contents and the parameters calculation methods are addressed in details. By developing stairwell evacuation experiments in different visibility conditions, the evacuees’speed distribution and behavior characteristics of upstream and downstream evacuations have been studied, and the main results are as follows:(1) By carrying out evacuation experiments of single upstream and downstream in 4 kinds of visibility conditions. The male individual ascent speed are 0.85 m/s,0.73 m/s,0.71 m/s and 0.54 m/s, decent speed respectively are 1.04 m/s,0.85 m/s,0.63 m/s and 0.61 m/s. The female individual ascent speed are 0.65 m/s,0.62 m/s,0.51 m/s and 0.48 m/s, decent speed respectively are 0.90 m/s,0.83 m/s,0.55 m/s and 0.47 m/s.(2) The experimental object in this paper, the female is affected by the visibility of the stairs more than the male, and the adaptability to the environment of the male is better than that of the female.In addition, under the synergistic effect of visibility and evacuation distance, the level of visibility within the staircase gradually replaces the physical ability and becomes an important factor of affecting the evacuation speed.(3) By carrying out evacuation experiments of cluster upstream and downstream in 4 kinds of visibility conditions, the time intervals and the average speed range of cluster evacuation have been obtained. Cluster ascent speed are 0.64-0.81 m/s,0.51-1.03 m/s,0.53- 0.83 m/s and 0.44-0.72 m/s. Cluster descent speed respectively are 0.96-1.36 m/s,0.54-0.83 m/s,0.40-0.63 m/s and 0.39-0.39 m/s.(4) Using the NIST staff statistical methods, evacuation speed-personnel density relationship has been obtained, which has certain difference with the fitting results of SFPE manual experience formula. Evacuation speed-flow density of upstream and downstream clusters is generally consistent with the linear relationship.