Using microtremor array survey to evaluate the possibility of piping-induced landslide dam failure

Landslide dams are formed when landslides move into mountain valleys, and potential flooding to the downstream area becomes secondary hazard of landslides. Sometimes, the potential flood threatens larger areas and more population than that by the landslide itself, so it is very important to find a quick method of evaluating the possibility of landslide dam failure. Generally, landslide dam failure can be caused by overtopping and piping. It is relatively easier to predict failure triggered by overflow because water level in the upstream area can be monitored. For those failure caused by piping, it is difficult to be predicted, because piping depends on the internal structure and composition of the landslide dam. If the internal structure of the landslide dam can be clarified, then it will become possible to evaluate the possibility of piping-induced landslide dam failure. In this paper, the possibility of using microtremor array survey to understand the internal structure of landslide dam and evaluate the potential of piping failure is examined.