THE EFFECT OF BREATHABLE-WATER PROOF SHEET AND DRAIN AS COUNTER MEASURE ON THE DIKE FAILURE DUE TO HEAVY RAINFALL AND WATER LEVEL RAISING

Many dike failures by the torrential downpour and rising river level are reported recently. As one of the key factors, the air behavior including the enclosure and consequent blow of air phase were observed in the saturation process of dike, whichaccelerated the failure of dike with air blow and resulting cracks on the surface. Therefore, it is needed to establish the counter measure method to prevent the degradation of dike by air blow. This research by the model test of dike failure under artificial rainfall and water level raising examined the effect of breathable-water proof sheet and drain as counter measure method on controlling the enclosure and blow of pore air in a dike. From the test results, the proposed counter measure method can restrain the accumulation of air phase and reduce the water level within the dike. As a result of this research, the usefulness of the breathable–water proof sheet and drain became clear, which can be greatly helpful to the disaster mitigation.