Abstract
The purposes of this study are to conduct a field survey on behaviour of group walking, and to propose a numerical simulation model for group walking and synchronization effect of tsunami evacuees. A field survey was conducted, and time-series data of group walking for tsunami evacuees were obtained at a tsunami evacuation drill using an evacuee tracking system. It was found that 90 percent of the evacuees walked in groups, and the others walked in a single or in a pair. Although the system needs accuracy enhancement of measurement, it was confirmed that each group was different in speed from the other groups. And it was also found that the group which passed through the measurement area first was the fastest in speed, the last group was the slowest in speed, and the other group was in the middle speed of the first group and the last group. A new model of group walking including a synchronization parameter was proposed, and a numerical simulation was conducted. It was found that the results of the simulation agree with the facts based on the field survey, although there were a few differences between the results of the simulation and the field survey in view of the speed of the group. Several reasons could be considered such as an effect of an evacuation leader at the front of the first group, and an applicability limit of the synchronization parameter model for groups consist of two or three persons.