STUDY ON HYDRODYNAMICS MECHANISM OF LARGE HIGHSPEED LANDSLIDE IN THE SET-OUT STAGE
大型高速滑坡启程流体动力学机理研究

During the process of large highspeed landslide in the set-out range,due to the lock segment suddenly snipped,shearing stress is released and thus pore water pressure is suddenly increased,which may produce a very high increase in temperature,convert the water in sliding zone into vapor and create steam pressure. The coupling of pore water pressure and steam pressure results in effective normal pressure reducing significantly under the sliding surface. This is the main reason for the sliding mass to acquire a high velocity in the set-out range. On the basis of triaxial experiment,the relation is discussed between pore water pressure and rates of shearing,and the formula is deduced of pore water pressure in the set-out stage of large highspeed landslide. The characteristics of temperature field of sliding surface is studied in the set-out stage. The depth of heat conduction by highspeed friction is calculated. Furthermore,the vaporization is analyzed of pore water in the sliding zone,and the value of steam pressure is calculated.