北川における漏水の変遷と地形及び堤防構造等の関係

抄録

The river embankment of Kita River in Miyazaki Prefecture has been experienced some floods in recent years. Many sand boils due to underseepage were observed repeatedly at around 13km from the river mouth. Our research group conducted some detail and large-scale field surveys at the sites.

This report shows the conditions of floods and sand boils as the premises of these survey results. In addition, the properties of the foundation ground and the topography also were introduced. The thick alluvial gravel layer that is widespread under the embankment is necessary condition for supplying water to the boiling sites. It is likely that the topography and the ground properties are important for boiling.