EXPERIMENTAL STUDIES ON SAFETY EVACUATION FROM UNDERGROUND SPACES UNDER INUNDATED SITUATIONS

Abstract

Many cities in Japan are located in alluvial plains, and the vulnerability of urbanized areas to flood disaster is highlighted by frequent flooding due to heavy rainfall or typhoon. Underground spaces are also flood-prone areas because those are below the ground, and water intrusion into underground space inflicts severe damages on human beings and urban functions and infrastructures. In order to reduce human suffering due to flood inundation in underground spaces and low-lying areas, needless to say, early evacuation is one of the most important countermeasures. This paper shows some experimental results of evacuation tests from underground spaces under inundated situations.The difficulties of evacuation from underground space was investigated by using three real-scale models (door, staircase, and car), and the limits for safety evacuation is discussed. From the results, it is found that water depth of 0.3–0.4m would be a critical condition for safety evacuation through staircase and door while 0.7–0.8m deep on the ground would be a critical situation for safety evacuation through the doors of the car. The relationship between the critical depth condition for the safety evacuation and the age of male subjects was also investigated by using the experimental results of real-scale door model tests and the Physical Fitness Survey results. A multiple regression model presented here properly reproduces the characteristics of the experimental results, such as the critical depth condition and its age-associated difference for safety evacuation. The same model is applied to the female's experimental results of real-scale door model tests and shows the overall distribution of the experimental results although the regression output still has considerable variation, especially in the young generation.