The Granular Flow Analysis For Volume Change Characteristics Of Gravel Soil Slope The Under Equivalent Rainfall Infiltration

Gravel soil slope as a kind of engineering structure widely exists in China’snorthwest, southwest and often encountered in the human engineering activities. Asthe medium of slope, gravel soil makes research quite difficultly because of itsdisorganized material structure, poor sorting and remarkable anisotropy. Alsoowning to the complexity of composition, the irregularity of structure distribution andexternal induced factors such as rainfall, gravel soil easily leads to engineeringdisasters including debris flow and landslide, which bring about the loss of people’slife and property. Existing research results is not very much about the physical andmechanical properties of gravel soils and gravel soil infiltration characteristics andrainfall induced landslide characteristics were less. Therefore, this text is tried toexplore physical and mechanical properties of gravel soil landslide under rainfallinfiltration, infiltration characteristics and features by the triaxial experiment, theindoor experiment to rainfall infiltration and large trough rainfall landslide model test,combined with particle flow numerical, and then provide powerful science basis forrainfall landslide disaster prevention and mitigation of gravel soils to. The mainresearch results are as follows:1. Conventional triaxial experiment (Cu) displays: Gravel soil takes the form offailure surface when shear failure; the stress strain curve has obvious step at differentmass density; The mass density and confining pressure have a combined effect.2. It generates stochastic model for simulation of gravel soil triaxial experimentbased on the secondary development on the original Fishtank with creating threedifferent shapes law of stone formation. It gets a set of mesoscopic parameters bycompared the triaxial experiment simulation and physical experiment, then providethe simulation parameters for initial mesoscopic equivalent rainfall landslides.3. Rainfall infiltration experiment was finished based on darcy seepage principle,the relation of infiltration speed of the Top, slope waist and slope toe between rainfallinfiltration experiment and model trough experiments was obtained: exponentialrelationship, logarithmic relationship, linear relationship. It provides equivalentinfiltration parameter for equivalent rainfall landslides simulation.4. It is with the background of rainfall model trough experiment to achieve equivalent rainfall landslide simulation. The results show that the horizontal andvertical displacements’ of top and waist place show the trend of nonlinear growth. Therainfall mainly affects the action of table slope infiltration layer. The large sheardeformation happens inside of slop with the rain continued. The slope porosity aregradually disappearing in the top and waist place of slope, but the porosity rate of theslope foot increases with the decrease before. It verify the reliability of the numericalsimulation with another group of experimental conditions on rainfall landslide modeltest and the equivalent of rainfall simulation can better realize rainfall landslide modelexperiment.