15th World Congress on Computational Mechanics (WCCM-XV)
8th Asian Pacific Congress on Computational Mechanics (APCOM-VIII)
31 July – 5 August 2022, Yokohama, Japan

Numerical Study on Damage of Tsunami Evacuation Building underTidal Wave and Debris Impact
Hiroyuki Omura1*, Naoto Mitsume2, Mitsuteru Asai3 and Daigoro Isobe41

Graduate School of Science and Technology, University of Tsukuba
1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8573, Japan, s2030186@s.tsukuba.ac.jp
2Division of Engineering Mechanics and Energy, University of Tsukuba
1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8573, Japan, mitsume@kz.tsukuba.ac.jp
3
Department of Civil Engineering, Kyushu University
744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan, asai@doc.kyushu-u.ac.jp
4
Division of Engineering Mechanics and Energy, University of Tsukuba
1-1-1 Tennodai, Tsukuba-shi, Ibaraki 305-8573, Japan, isobe@kz.tsukuba.ac.jp

Key Words: Tsunami evacuation building, Debris impact, Fluid-structure interaction,
Partitioned FSI analysis, Particle method, ASI-Gauss method, Improved ERP model

Robustness of a tsunami evacuation building is one of the most important problems in protecting
lives and properties against tsunami. To ensure robustness, it is necessary to design withconsideration of strict external forces, including dynamic fluid force and debris impact force,
caused by tsunami.
In this research, we numerically simulate behaviour of a tsunami evacuation building under tidal
wave and debris impact to investigate trend of the forces due to tsunami. Partitioned fluidstructure interaction analysis scheme coupled with stabilized ISPH (Incompressible Smoothed
Particle Hydrodynamics) method [1] and ASI (Adaptive Shifted Integration)-Gauss method [2] isapplied for the simulation. The ISPH method is a semi-implicit particle method and suitable forfree surface flow problem such as tsunami. The ASI-Gauss method is a finite element method
using linear Timoshenko beam elements and can express a plastic hinge at any position in anelement by shifting a numerical integration point. Besides, improved ERP (Explicitly RepresentedPolygon) wall boundary model is used as interface modelling between fluid and structure domain.
This model accurately satisfies boundary conditions on solid walls and can directly calculate fluid
force exerted on the walls.
As validation of the proposed FSI coupling scheme, we solved free fall problem of a beam
member and dam break problem with an elastic obstacle. Results of these analysis showed thatthe coupling scheme can obtain precise solution. Furthermore, we conducted a simulation of atsunami evacuation building under tsunami and debris. Specification of the building wasdetermined according to current tsunami evacuation building design standard in Japan [3]. Basedon the results, damage of the building caused by tidal wave and debris impact was verified.
REFERENCES[1] M. Asai et al., A Stabilized Incompressible SPH Method by Relaxing the Density Invariance
Condition, Journal of Applied Mathematics (2012), Article ID 139583.
[2] D. Isobe, Progressive Collapse Analysis of Structures: Numerical Codes and Applications,Elsevier, (2017)[3] NILIM, Practical Guide on Requirement for Structural Design of Tsunami Evacuation
Buildings, Technical Note of NILIM (2012), (in Japanese).