DEBRIS FLOW CONTROL ONCE UNDER WAY

Efficacies of the newly devised methods to control debris flow once under wayare discussed experimentally and numerically. These methods are retarding andstoring the debris flow by the series of alternately projecting groynes, stopping thedebris flow front by removing water from it through the grating layed on the bedor on the channel wall, and changing the flow regime from inertial to macro-viscousrange, I. E., slow down the velocity by adding a kind of chemicals.First, a numerical simulation method which is useful to discuss the behaviour ofdebris flow around such structures is presented. Then, the processes of retardation, deformation and stoppage of debris flow by the structures are examined by both theflume experiments and the numerical simulations.Second, the characteristics of macro-viscous flow produced by adding water ab-sorbent into debris flow are observed experimentally and a new flow equation to ex-plain those characteristics is presented. After that, possibility and the problems tobe cleared for the practical use are pointed out.Efficacies of the newly devised methods to control debris flow once under wayare discussed experimentally and numerically. These methods are retarding andstoring the debris flow by the series of alternately projecting groynes, stopping thedebris flow front by removing water from it through the grating layed on the bedor on the channel wall, and changing the flow regime from inertial to macro-viscousrange, I. E., slow down the velocity by adding a kind of chemicals.First, a numerical simulation method which is useful to discuss the behaviour ofdebris flow around such structures is presented. Then, the processes of retardation,deformation and stoppage of debris flow by the structures are examined by both theflume experiments and the numerical simulations.Second, the characteristics of macro-viscous flow produced by adding water ab-sorbent into debris flow are observed experimentally and a new flow equation to ex-plain those characteristics is presented. After that, possibility and the problems tobe cleared for the practical use are pointed out