Author(s): Joongcheol Paik; Youngil Kim
Linked Author(s): Joongcheol Paik
Keywords: Debris flow; Culvert; Laboratory experiment; Channel slopes; Volume concentration
Abstract: Debris flow is one of the most hazardous natural processes in mountainous regions. The degradation of discharge capacity of drainage facilities due to debris flow may results in damages of properties as well as casualty. Understanding and accurate reproducing flow behaviour of debris flows at various geometrical conditions, especially channel slope, is prerequisite to develop advanced design criteria for drainage facilities to prevent such damages. We carried out a series of laboratory experiments of debris flows in a rectangular channel of constant width with an abrupt change of bottom slope. The experimental flume consists of an approaching channel part with the bed slope ranging 18° to 25° and the test channel with slope ranging from 0° to 12° which mimics a typical drainage culvert. The experiments have been conducted at various flow conditions with different channel slopes and sediment volume concentration of debris flows to investigate those effects on the behaviour of debris flows. The results show that the depth of debris flow with sediment volume concentration of 0.7 is approximately 50% higher than that of fresh water flow at the same flow rate. The results also quantitatively show that variation of flow depth and features of sediment deposit in the test channel depend on the slopes of both approaching and drainage channels, sediment volume concentration and sediment material property.
Year: 2011