It's difficult to escape from the top floor to the ground floor in a high-rise building, so having an escape floor standing in a siege midfloor will become an important method of escaping in case of a fire. Therefore to investigate the suitable population density to design the escape floor standing in a siege midfloor, we used the following method: (1) Assuming the comfortable escape area, from the experiment that the subject stands in the center of the circle and the object approaches to the subject, we measured "unbearable" distance and "began to feel the presence". (2) For investigating the interval length in the short period of time, we measured the interval length by people waiting for the train in one line during rush hour. (3) For investigating the actual crowd density, we measured the crowd waiting for a change of the signal at a crossing. We investigated the effect of the season by comparing with the summer and winter data. As a result, we found the crowd density stayed without the feeling of oppression in 0.3∼0.4 [p/m²], stayed in a short period of time in 1.5[p/m²], and the most crowd density in 2.5∼2.8 [p/m²], to design escape floor standing in a siege midfloor.

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Planning and design for fire safety has been changed gradually in recent years, because of the increasing high rise buildings, large atrium and those diversity. The living environment has been changed, however, the walking speed going down the stairs has not changed for 30 or 40 years in the plan and design for fire safety. In this study the present data for walking speed at the stairs in winter and summer seasons in the field to compare the conventional one concerning the horizontal walking speed, the vertical walking speed and the relationship between the walking speed of the group and the density of those. The results showed that the walking speed in the present day faster than the conventional data, and that of in winter faster than the summer data in compliance with the air temperature and the psychological condition at that time so forth. The walking speed for elderly and the disabled people were measured to evaluate the capability for the movement at the stairs, and the results revealed that they were not influenced so much by the temperature and the psychological pressure.

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In this paper, burning rates measured during unsteady combustion of small pool fires using three different fuels are discussed. Unsteady combustion is obtained by a batch test in which the fuel level in the tank decreases after ignition. We measured the burning rates, the fuel temperature, and the tank temperature of three different fuels. Experimental results allow the following conclusions:
1. Three major processes, so called preheating, transition and boiling process, were found from the fuel temperature change curves of small pool fires during unsteady combustion.
2. Burning rates of heptane and kerosene increase when fuel temperatures and tank temperatures go up. The burning rates in the boiling process are about 1.64 for heptane and about 1.3 for kerosene times as much as those during the preheating process.
3. Preheating, transition and boiling processes were easily found from the fuel temperature change curves of the methanol pool fire. Nevertheless methanol does not show a distinct increase of burning rate.
4. The reason for various burning rate changes of small pool fires are clearly explained by the calculation of fuel evaporation using measured burning rates and fuel temperatures. Heptane and kerosene fires change their burning rates because both evaporation heats and preheating heat are not large. The evaporation heat of methanol is the largest and it is about three or five times bigger than that of heptane and kerosene. This is one of the reasons for the constant burning rate of methanol.
5. From the above discussion, the concept of maximum burning rate ratio (MBRR) is introduced to explain the burning rate change of various fuels. MBRR becomes larger as the number of carbon atoms in fuel increases.
Finally, the above mentioned phenomena will happen when heat supply by convection and conduction are not so small compared with by radiation. In medium and large size pool fires, sufficient heat will be supplied from the flame, mainly by radiation, so that the above mentioned preheating and transition processes may not easily be found. In small pool fires, burning rates are strongly affected by circumferential conditions such as fuel and tank temperatures. This may be one reason for various burning rates obtained by experiments using the same tank size and fuel.

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During the investigating cause of a fire, the organic insulating materials of electric wires and distributing fixtures carbonized by the fire are found out. It is necessary to make clear the electrical characteristics of carbonized materials. The studies on the relation between the heating temperature of carbonized wood and electrical resistance has been carried out so far, but it is not studied enough for using the investigating cause of a fire. Then the authors carried out the experiment to investigate the effects of heating temperature on electrical characteristics of carbonized organic insulating materials.

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