| In this study、 the authors performed a series of laboratory experiments to examine the drift motion of ice floes driven by bore-like tsunamis. The work involved investigating the disintegration of a tsunami into a train of undular bores with floating ice models on the surface. The experiments were recorded using digital cameras、 and ice floe positions were determined as a function of time from digitalized pictures using the PTV image analysis technique. A number of interesting findings were made from these experiments. It was observed that the run-up heights of wave fronts increased by over 70% in the wave propagation process、 and that the time-series waveforms of undular bores closely corresponded to model tracer velocities. This means that bore fronts are capable of causing sudden large acceleration in the movement of ice floes. The outcomes highlighted the potential risks of these masses of ice、 which can be hazardous to river structures such as bridge piers、 floodgates and intake screens. |
