ICCE 2022

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MODELLING OF DEBRIS MOTION DRIVEN BY TSUNAMI WAVE BREAKING. (2023). Coastal Engineering Proceedings, 37, management.99.


When a giant tsunami approaches onshore, offshore vessels and other floating objects move following the current of the tsunami. Some of the waterborne debris are transported to tsunami inundation areas and those debris impact buildings. For evaluations of debris impact loads, types of debris having the potential to impact and damage the structures are identified by considering debris impact hazard region. According to ASCE7-22, the debris impact hazard region shall be determined by the empirical model proposed by Naito et al. (2014) in a simple manner. Furthermore, numerical debris transport modelling using massless tracers also shall be permitted to use for the determination. On the other hand, numerical debris tracking (nDT) modellings which solve the equation of motion of debris have been developed (e.g., Kihara and Kaida, 2019). In this study, a surface roller modelling is incorporated into the nDT model of Kihara and Kaida (2019) to simulate debris motions driven by tsunami wave breaking. To validate the model, simulations of hydraulic experiments focusing on the motion of offshore debris reported by the Nuclear Regulation Authority (NRA) of Japan are carried out (Oda et al., 2021).


Naito, C., Cercone, C., Riggs, H.R., and Cox, D. (2014): Procedure for site assessment of the potential for tsunami debris impact. Journal of Waterway, Port, Coastal, and Ocean Engineering, ASCE, vol. 140 (2), pp. 223-232.

Kihara, N. and Kaida, H. (2020): Applicability of tracking simulations for probabilistic assessment of floating debris collision in tsunami inundation flow. Coastal Engineering Journal, Taylor & Francis, vol. 62(1), pp. 69- 84.

Oda, Y., Hashimoto, T., and Hashimoto, A. (2021): Evaluation of impact force acting on tsunami seawall due to water borne debris. Journal of Japan Society of Civil Engineers, Ser.B2, Coastal engineering, vol. 77 (2), pp. I_205-I_210.

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Copyright (c) 2023 Naoto Kihara, Hideki Kaida, Chiaki Tsurudome