EXPERIMENTAL INVESTIGATION ON THE ESTABLISHMENT OF RIVER CONTROL FACILITY OPERATION AGAINST THE EFFECTS OF TSUNAMI DRIFT

This report presents an investigation for the establishment of river control facility operation against tsunami run-up in rivers. The tsunami generated by the 2011 Tohoku Pacific-Coast Earthquake devastated coastal areas in Japan and was characterized by the generation of tremendous number of tsunami debris and drifts. In addition, in Hokkaido where ice formed in rivers, broken ice pieces were found in the field survey. The main aim of this report is to propose an optimum sluice operation in the event of tsunami considering the existence of ice floes. An experimental model of a sluice gate is developed with ice floe models on the water surface and two types of tsunami waveform are generated in the flume. The result showed that the gate openness can partially attenuate the wave impact load. However, it is confirmed that the presence of ice floes can cause an accidental jamming and an increase in the wave force, which can result in the functional failure of the sluice gate