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The issues concerning evacuation from high-rise buildings in emergency has led to a call for extensive investigation to a great number of scholars with different professional background. In this article, we proposed a simplified calculation method of evacuation time using stairs, elevators, or a combination of both in high-rise buildings. We studied the evacuation efficiency of both small and large crowds evacuated from different building floors based on the proposed methods. We also discussed the optimal evacuation strategy using a combination of stairs and elevators. We found that the efficiency of elevator evacuation is better than stairs with a small crowd, and the preponderance became much clearer with the increase of building floor; it was not suitable to use elevators as vertical transportation facilities under the situation with a large crowd and the situation of evacuation from low building height. The conclusions in this article are hoped to be useful for crowd management in emergency evacuation. [ABSTRACT FROM AUTHOR]

The vertical and horizontal distribution of CO concentration in the tunnel fire under longitudinal ventilation was studied by scale modeling technique. A 1/4 rectangular tunnel model of 0.4m width, 0.8m height, and 3.48m length was constructed. A series of experiments were conducted with five different ventilation velocities and with n-Heptanes pool fires in side-length pan of 15cm. It was found that there exists a critical velocity at which the mass loss rate is the highest, and when the smoke is laminar flow, the stratification of CO concentration is more distinct than near the fire source. When the smoke is turbulent flow, the stratification of CO is indistinct. The maximum CO concentration decreased along the tunnel model, and the delaying time of the maximum CO concentration decreased with the increase of ventilation velocity. [ABSTRACT FROM AUTHOR]

Based on the analysis of comparability, a bench-scale (1:4) facility with the configuration of "fire room-long passage-remote room" is designed to study the spatial distribution and risk of CO in building fire. A series of experiments are carried out on the facility. It is found that CO concentration increases with the height of probes in the non-firesource-field. In the long passage, CO concentration decreases with the distance from the firesource. Additionally, CO concentration varies greatly at the upper part, but is uniform at the lower part in the long passage. However, CO distribution in the remote room is just the opposite. In addition, CO concentration in the remote room is greatly influenced by various openings. These characteristics of CO distribution in the non-firesource-field indicate that the long passage and the remote room should be treated differently in research. Meanwhile, the present article puts forward the concept of index of toxicity to analyze the smoke toxicity in the non-firesource-field, which has the superiority to be used to assess the risk grade of non-firesource-field. [ABSTRACT FROM AUTHOR]