Whole Course Analysis on Hydrokinetics Mechanism of Touzhai Gully Landslide

Abstract:

A giant highspeed landslide occurred in the Touzhai Gully of Yunnan province on September 23rd,1991.From the points of view of hydrokinetics,this paper presents an analysis of the mechanism of highspeed and long runout all over the course and several conclusions are drawn.In the setout stage,the coupling of pore water pressure and vapor pressure resulted in substantial reduction of the effective normal pressure at the slipped surface.In the shortrange stage,the highspeed sliding mass formed the aerofoil like aerodynamics effect.The high perceentage of the potential energy of the sliding mass was transferred into the kinetic energy.Consequently,the sliding mass flew over the small hill on the slope.In the long runout stage,due to the action of air vortex,the sliding mass changed the style of motion from flying to fragment flow,which was similar to the kinematic characteristics of debris flow at high speed.