Simulation and Experiment of Mass Evacuation to a Tsunami Evacuation Tower

A 3D mass evacuation simulation using precise kinematic digital human (KDH) models and an experimental study are discussed. The tidal wave associated with the large tsunami caused by the Great East Japan Earthquake was responsible for more than 90% of the disaster casualties. Unfortunately, it is expected that other huge tsunamis could occur in Japan coastal areas if an earthquake with magnitude greater than 8 occurred along the Nankai Trough. Therefore, recent disaster prevention plans should include evacuation to higher buildings, elevated ground, and construction of tsunami evacuation towers. In the evacuation simulation with 500 KDHs, the mass consists of several subgroups. It is shown that the possible evacuation path of each group should be carefully determined to minimize the evacuation time. Several properties such as evacuee motion characteristics of KDHs, number of evacuees, exit gates and, number of injured persons were carefully considered in the simulation. Evacuee motion was also experimentally investigated by building a test field that simulates the structure of an actual tsunami evacuation tower for accommodating approximately 120 evacuees. The experimental results suggest that an appropriately divided group population may effectively reduce the overall group evacuation time. The results also suggest that the fatigue due to walking during evacuation adversely affect the total evacuation time, especially the ascent of stairways. The experimental data can be used to obtain more accurate simulations of mass evacuation.