Akihiko Hokugo

Mechanism For The Upward Fire Spread Through Balconies Based On An Investigation And Experiments For A Multi-story Fire In High-riseapartment Building

Summary of experiments for the investigation of a fire which caused an upward fire spread for over 12 floors through balconies in a high-rise apartment complex is reported. The experiments include indoor tests to obtain fire properties of vertical PMMA fences and outdoor tests with a full scale model of the balcony. The test results suggest significance of the increase of total flame height through merging of flames and cooperative effect of the burning of PMMA fences and combustibles on the balconies for the generation of a tall flame enough to cause ignition on the upper floor.

A Post-Earthquake Fire Spread Model considering Damage of Building Components due to Seismic Motion and Heating of Fire

KEISUKE HIMOTO, KYOSUKE MUKAIBO, RYO KURODA, YASUO AKIMOTO, AKIHIKO HOKUGO, and TAKEYOSHI TANAKA Disaster Prevention Research Institute Kyoto University Gokasho, Uji, Kyoto 611-0011, Japan Graduate School of Science and Technology Ritsumeikan University Noji-Higashi, Kusatsu, Shiga 525-8577, Japan Ichijo Corporation Kiba, Kohtoh, Tokyo 135-0042, Japan Mitsubishi UFJ Research and Consulting Imabashi, Chuo, Osaka 541-0042, Japan Research Center for Urban Safety and Security, Kobe University Rokkodai 1-1, Nada, Kobe 657-8501, Japan

Risk and Behavior of Fire Spread in A Densely-built Urban Area

A fire staring in a densely-built urban area easily spreads to adjacent buildings. In the case of large earthquakes in which multiple fires may break out simultaneously, the spread of such fires may overwhelm the ability of firefighters and damage large areas. In this study, fire spread simulations were carried out in order to investigate behavior of fire spread in Kyoto Higashiyama area, one of the representatives of densely-built urban areas in Japan. A physics-based model was used in which the following mechanisms of fire spread are considered: thermal radiation heat transfer from fire-involved buildings; elevation of ambient temperature by wind-blown fire plumes; and spotting ignition by firebrands. The risk of fire spread was also analyzed by the Monte Carlo method to evaluate the expected magnitude of loss. The effect of uncertainty of the location of fire origin and the weather conditions was investigated.

A Physics-Based Model for Post-Earthquake Fire Spread Considering Damage to Building Components Caused by Seismic Motion and Heating by Fire

The prototype model previously developed by the authors was improved in order to simulate the behavior of fire spread in an earthquake-affected urban area. In the new model, seismic motion and heating by fire are both considered as the causes of damage to building components. The damage affects the burning behavior of a fire-involved building, as well as the behavior of building-to-building fire spread. For validation of the new model, a simulation of the fire spread that followed 1995 Kobe earthquake was conducted. The behavior of the fire spread obtained by the numerical simulation was compared with the observed data. Reasonable agreement was obtained with regard to the number of burned buildings.

Investigation of a large wooden gymnasium fire- Its documentation, estimation of the fire scenario by experiments and evaluation of the structural properties of surviving timber elements

This is the first fire in Japan of a large wooden gymnasium with a large-scale glue-laminated timber structure which was totally burnt with a rapid flashover (FO). The fire deserves close attention for not only rapid FO in a large enclosure but also availability of extremely good documentation on the fire. The extent of carbonization of the members that was collected when the building was dismantled and its structural property were measured. A series of burning tests of the combustibles stored in the source of the fire, conducted to clarify why the fire spread so rapidly in the gymnasium where a FO had been least anticipated and to make guidelines to prevent fire from spreading rapidly.

The Great East Japan Earthquake and Tsunami: Lessons for Land Use

In this chapter, we examined salient points during the reconstruction period in order to ensure security against future disasters and at the same time to restore people’s lives and local communities lost in the disaster, through observation of land use management in the reconstruction after the tsunami caused by the Great East Japan earthquake (GEJE) in 2011.

VELOCITY AND TRANSPORTATION ABILITY OF TRANSPORTING VULNERABLE PEOPLE DURING TSUNAMI EVACUATION DRILL IN A COMMUNITY: Outdoor evacuation with rollator, transport chair, wheelchair and cart in Sinyo Bokomi, Kobe, Japan@@@神戸市真陽地区におけるシルバーカー、介助車、車いすおよびリヤカーを用いた屋外の搬送避難

The purpose of this study is to establish a practical evacuation plan in a living area. To reduce fatalities, supporters in a community would use some instruments to transport vulnerable people for evacuation from a tsunami. An evacuation drill was conducted in Shinyo Bokomi, Kobe city, Japan in case of tsunami. On this occasion, evacuation supporters transported vulnerable persons to an evacuation destination using a rollator, a transport chair, a wheelchair or a cart. As the result of the drill, every evacuation trial have completed earlier than the estimated tsunami hitting time. In this study, we calculated evacuation transportation ability and evacuation transportation quantity. The results of the measurement were as follows. Evacuation transportation abilities of a rollator, a transportation chair, a wheelchair and a cart were 3.7person km/h, 5.1person km/h, 5.4person km/h and 4.6person km/h respectively. Evacuation transportation quantities were a rollator 3.7person km/h, a transport chair 5.1person km/h, a wheelchair 5.4person km/h and a cart 2.3person km/h in this measurement. In the evaluation meeting, it turned out that rescue order sheet worked effectively in the drill. We suggest that communities should incorporate using those instruments into their evacuation plans and put them to practical use in case of tsunami.

Households’ Risk Perception and Behavioral Responses to Natech Accidents

This study analyzes data on households’ risk perception and protective behavior following a natural disaster triggered technological accident (Natech accident) that occurred at an industrial park in Sendai during the Great East Japan Earthquake and Tsunami, on 11 March 2011. The results indicate that some households carried out multiple evacuations and that households’ risk perceptions changed throughout the Natech accident evacuation process. Risk perception differed according to household location and demographic characteristics. We also found differences in the protective measures adopted for households in different locations. Specifically, those living closer to the Natech accident tended to evacuate immediately, whereas those living further away tended to shelter in place. Wind direction is discussed as a factor that influences households’ risk perception and evacuation response to a Natech accident. The findings of this study advance knowledge of household behavior in response to a Natech accident and can assist emergency managers in developing strategies for better management of evacuation processes.

EXPERIMENTAL STUDY ON STAIR ASCENT TRANSPORTATION FOR VULNERABLE PEOPLE: Comparison by types of transportation; giving a piggyback ride, carrying a handy stretcher and carrying a wheelchair@@@背負い・簡易担架・車いすによる階段上昇搬送比較

This study is aiming to compare stair ascent transportation speed and physical burden of evacuation supporters according to the types of stair ascent transportation for vulnerable people experimentally. In this study, we measured heart rate of the supporters to indicate physical burden during the transportation. The subjects of this experiment were male students, age of 18-24. Experimental conditions were the ways of stair transportation and the weight of vulnerable people. The types of stair transportation were giving a piggyback ride, carrying a handy stretcher and carrying a wheelchair. Each experimental trial was video-recorded for measurement of ascent speed and observing supporters movement. As a result, this research proves that the weight of vulnerable people has an impact on the ascent speed and physical burden of supporter and giving a piggyback ride is the fastest in all ways of stair ascent transportation but the physical burden for a supporter is the heaviest.

Venue Suitability for Large-Scale Events from the Viewpoint of Safety Measures

This study analyzes recent crowd disasters at mass events by examining event planning and event security planning, analyzing disaster videos, conducting interviews and on-the-spot investigations and reviewing disaster investigation reports. Analysis reveals that these disasters occurred related to three venue-suitability factors: (1) projected visitor number which determines most of venue safety measures; (2) venue space planning including event content types; and (3) access route for crowd flow. Also shown are the influences of venue topographic and structural conditions on access route for crowd flow. At most of those disaster sites, access routes were highly-fenced areas like tunnels and bridges which do not lead to escape routes. Where these venue-suitability factors are not appropriately arranged, preventing the excessive accumulation of high-density crowd is difficult, even if appropriate security measures are taken. To avoid these crowd disasters, it is essential to judge venue suitability during the event planning stage.