• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.590-595
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• 2020

In this study, the small-scale collision experiments using a pendulum principle were carried out to evaluate the safety of the reinforced concrete building selected as a tsunami evacuation building due to the collision of the waterborne debris represented by ships. The experimental parameters were set as impact velocity, mass and length of the drifted ship. In this paper, the maximum impact force, impact duration, impact waveform and restitution coefficient affecting building response were investigated in detail. As a result, the impact force waveforms were distributed as a triangle in most of the experimental results, but became closer to a trapezoid as the length of the collision specimen increased. This is the very important result in calculating the momentum (impact waveform area) affecting building response, Furthermore, the restitution coefficients were constant regardless of the impact velocity, but they varied depending on the mass and length of the waterborne debris. However, the restitution coefficient for the mass per unit length of the waterborne debris can be evaluated.

• Journal of Ocean Engineering and Technology
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• v.38 no.5
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• pp.282-293
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• 2024

This study examined the collision dynamics between tsunami-driven drifting containers and port cranes, prompted by risks from the recent 7.6 magnitude earthquake and tsunami off Noto Peninsula, Japan. Hydraulic experiments were conducted to analyze container drift and collision forces using motion analysis software (DIPP-Motion) and a load cell installed on a crane leg model. The key parameters included the tsunami wave height, container weight (empty and loaded), initial position, and revetment type. The results suggested that higher tsunami wave heights led to more extraordinary inundation, allowing containers to float more efficiently, reducing bottom friction, and increasing drift speed and collision forces. The collision speeds ranged from 1.59 to 2.48 m/s, with collision forces of 45.18 to 77.68 N, representing increases of 6.45 to 15.58 times than no object. Heavier containers required deeper water to float, resulting in lower drift and collision speeds (0.88-0.89 times that of lighter containers). The wave-absorbing revetment caused higher flow velocities, producing collision speeds and forces 1.32-1.48 times greater than the vertical revetment. These findings highlight the importance of considering the tsunami magnitude, container weight, initial position, and revetment type in design, with face-to-face contact conditions crucial for estimating the maximum collision forces and preventing future tsunami damage.