| We made the feasibility study to investigate high permeable layers in the shallow zone by 3D geophysical method. Sand boil phenomenon are often observed at the protected low land, when high flood water level of river is occurred due to concentrated heavy rain. Sand boils are indicated the existence of paths for water current flow in the underground. The existence of paths for water current flow is the reason of piping phenomenon and impact the soundness of a levee. To take a countermeasure against levee crevasse and overflood due to piping phenomenon, it is important to investigate paths for water current flow three-dimensionally and in detail. So, we applied the 3D passive surface wave method and electrical method to investigate sand layers could be paths for water current flow. In this presentation, we show the 3D model measured by 3D geophysical methods and the consideration and conclusion of this study. |
