Experimental speculation on scour due to jet flow focusing on the soil particle and the soil element scale level

Abstract

Scouring due to tsunami causes a decrease in the bearing capacity of structures. Disaster of the breakwater with scour due to tsunami overflow was occurred at Hachinohe-port in East Japan Great Earthquake. The present study attempted to explicate the scouring mechanism due to overflow focusing on the tractive force and the pore water pressure in the sediment ground by using two-type geomaterials that is different permeability. As a result, scour was occurred with tractive force. The scour profile had same profile as proposed by Yeh et al. when sandy soil used. However, we found that the excess pore water pressure was generated in the ground due to jet flow, and liquefaction was occurred. Therefore, we need to recognize that the liquefaction-layer is generated due to overflow.