Examining Velocity Estimation Equations of Debris Flow Using Small-scaled Flume Experiments

摘要

With its rapid velocity and wide deposition, debris flow is a natural disaster that causes loss of human life and destruction of facility. To design effective debris barriers, impact force of debris flow should be first considered. Debris flow velocity is one of the key features to estimate the impact force of debris flow. In this study, we conducted small-scale flume experiments to analyze flow characteristics of debris flow, and determine flow resistance coefficients with different slope gradientsand sediment mixtures. Flow velocity significantly varied with flume slope and mixture type. Debris flow depth decreased as slope increased, but difference in depth between sediment mixtures was not significant. Among flow resistance coefficients, Chezycoefficient (Ci) showed not only relatively highest goodness of fit, but also constant value (20.19 m"1'2 s"1) regardless the scale of debris flow events. The overall results suggested that Ci can be most appropriately used to estimate flow velocity, thekey factor of assessing impact force, in wide range of debris flow scale.