Research On Mechanlcs Charaterstlcs And Machanism Of Deformation And Failure Of Unsaturated Soll-Rock Mixture

For colluvial landslides, under heavy rainfall or continued rainfall, it is easily instability in saturated-unsaturated state. Experiment and theoretical research of the mechanical characteristics and its influencing about unsaturated soil-rock-mixture is always hot issues. This page developed soil-rock-mixture mesoscopic institutions of randomly generated system, hich is based on gradation of the arbitrary convex boundary shape stone. Through characteristics of soil-rock interface parameters, including stone quantity, saturation and the differences of drought-wet circulation about the unsaturated soil-rock-mixture, The research have performed comprehensive study on the stress-strain relation, shear dilatancy/shear shrinkage, the laws of hardening/softening, he strength characteristics, and the the mechanism of deformation and failure, this paper obtained the following results:1. Based on the systematic summary of present research situation of unsaturated soil-rock mixture, researching methods, main outcomes, and analysing the exsisting problems, this paper presents its major research contents and methods.2. Using Fortran programming language developed random convex polygons generation system of soil-rock mixture, mbed in finite element program, so as to realize the function of the numerical calculation model test.3. Through the dual axle numerical experiments, this paper studied deformation strength properties and failure mechanism of unsaturated soil-rock-mixture under different interface parameters of soil-rock. The result shows that:when interface friction factor of soil-rock is small, nsaturated soil-rock-mixture performance for "medium shape" failure mode, as friction factor increases, rock and soil deformation coordination consistent, the higher the peak intensity, inally show "overall shape" destruction.4. Through numerical test under the different the rock block contents saturation, this paper studied the deformation strength characteristics, failure mechanism of soil-rock mixture.The research show that:the higher gravel content of unsaturated soil-rock-mixture, the lower peak intensity; Along with the saturation increases, peak intensity will reduce the more significant, dilatancy properties will be more apparent.5. Unsaturated soil-rock mixture is a typical porous medium, and its permeability and particle size, shape and saturation have close relationship. Through double-axis permeability experiments, research mesoscopic seepage features of unsaturated soil-rock mixture, and the influence coefficient rule. Results show that:permeability of unsaturated soil-rock mixture reduced with gravel content increased, but increased with saturation increases when the soil and stone contact closely and the fragment stone Do not permeate.6. The different path of saturate changed, matric suction are different, hrough numerical test under the different dry wet cycling times, this paper studied that:along with the increase of number of dry-wet circulation, the strength of unsaturated soil-rock mixture is decreased obviously, This is also a instability factor of colluvial landslides under the rainfall infiltration/evaporation conditions.