MODEL EXPERIMENT AND NUMERICAL SIMULATION ON TSUNAMI-DRIVEN MOTON OF A GROUP OF DEBRIS OBJECTS

Abstract

 Tsunami debris objects are a cause of expanding disaster and/or obstructing emergency response activities. Their motion has been experimentally investigated, and practical calculation models have been also developed for estimating it. This study focuses on a group of debris objects in which individual objects can collide with each other. At first, motion of the group was experimentally analyzed. The experiment showed that the center of mass of the group of debris objects was similarly moved in the direction of tsunami inundation flow even in different conditions of the size of debris objects and the initial setting of debris position. Dispersion of individual debris objects obviously took place in the direction of tsunami inundation flow, comparing to that of the cross direction. The significant dispersion was caused when the flow hit the debris group. A tsunami numerical simulation model of T-STOC could calculate motion of the center of mass of the group in error by less than plus and minus 100 percent. For further improvement of calculation models to estimate motion of debris objects, interaction between the objects and tsunami flow should be included in the calculation.