抄録
Formation of natural dams is a common process in gorges of the flow route of relatively steep gradient mountain rivers. A tremendous part of the flow accumulates upstream once such a dam forms in the way of regular flow. Consequently, the accumulated water submerges a large area causing inundation upstream and posing the threat of debris flow and flooding downstream. Once the dam is unable to hold the huge amount of amassed water destruction of the dam begins and brings debris flow disaster into the downstream areas, creating great havoc.
The present study attempts to discuss the experimental observation of different types of failure in a dam, e.g., slope failure at the frontal part and bed load transportation and debris flow at the body part by making trapezoidal shape of a natural dam. Experiments have been conducted using almost uniform-sized gravel. The collapse mechanism and its progress in the upstream direction show the trends of collapse in a progressive fashion, starting from downstream and advancing upstream.
