Simulation and Experiment of Mass Evacuation to a Tsunami Evacuation Tower

A three-dimensional (3D) mass evacuation simulation using precise kinematic digital human (KDH) models and an experimental study are discussed. The flooding associated with the large tsunami caused by the Great East Japan Earthquake on Mar. 11, 2011, 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 eight occurs along the Nankai Trough. Therefore, recent disaster prevention plans should include evacuation to higher buildings, elevated ground, and constructed tsunami evacuation towers. In this study, evacuation simulations with 500 KDHs were conducted. The simulations consisted of several subgroups of KDHs. 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 simulations. Evacuee motion was also experimentally investigated by using a multistoried building to replicate the structure of an actual tsunami evacuation tower that could accommodate approximately 120 evacuees. The experimental results suggest that an appropriately divided group population could effectively reduce the overall group evacuation time. The results also suggest that fatigue due to walking during evacuation adversely affects the total evacuation time, especially in the ascent of stairways. The experimental data can be used to obtain more accurate simulations of mass evacuation.