| Eluvial gravel soil is a kind of soil-rock mixture. Its composition factors areextremely complex, which was mainly constituted by weathering, unloading, alluvial,deluvial, etc. Due to the complexity of composition, the irregular of structuredistribution, brings to the research on its engineering properties and mechanicalproperties of the great difficulties. With it as a substance or sliding of the landslide,the slope is widely distributed in the southwest and northwest regions in China, andoften caused by rainfall or engineering activities to slip by the enormous economiclosses and casualties. Based on eluvial gravel soil in the mount Zhaoshan of hunan asthe research material, based on the indoor rainfall landslide model test, the furtherstudy of1.2mm/min and1.6mm/min two kinds of rainfall intensity,22°and31°Angle of two kinds of slope under the condition of eluvial gravel soil landslide modelof pore water pressure, soil pressure, relative displacement and the response law ofwetting front, rainfall intensity and slope Angle on eluvial gravel soil landslidedevelopment and the influence of deformation and failure. The main research resultsare summarized as follows:1. Indoor rainfall landslide model test device is developed, including the portablemodel slot width and the artificial rainfall system.2. By conducting rainfall rate test, debug the rainfall system performance, rate ofrainfall intensity and rainfall evenness, the1.2mm/min and1.6mm/min two kinds ofrainfall intensity is designed, rainfall evenness biggest reached65%, the lowest52%.3. Through model test, rainfall intensity and slope Angle are analyzed and theinfluence of deformation and failure of landslide development. Research shows that:(1) The same slope Angle, the greater the rainfall intensity, or the same rainfallintensity, the greater the slope Angle, slope table earlier channel, the runoff of water inthe slope foot began to the earlier, the slope erosion phenomenon is more serious.(2)The slope Angle is constant, the greater the rainfall intensity, the pore pressureresponse more quickly, the faster the rainfall rate of pore water pressure, the faster andreach the stable state; Rainfall intensity is constant, the smaller the slope Angle, thepore pressure response more quickly, rainfall the faster the pore pressure increase,eventually pore pressure change is larger.(3) Slope Angle must be, the greater therainfall intensity, and rainfall intensity, certain slope Angle is smaller, the faster response and rainfall soil pressure of soil pressure, the more obvious increasing trend.(4) The same slope Angle, the greater the rainfall intensity, or the same rainfallintensity, the smaller the slope Angle, rainfall wetting front response more quickly, atthe same time the migration distance, the greater the local table appeared after stablerunoff, wetting front migration velocity affected by rainfall intensity is not big.(5)Deformation failure of eluvial gravel soil landslide is closely related to rainfallintensity, but not the greater the rainfall intensity, the greater the degree of slopedeformation and failure because the rain is better than the general assembly on slopetable prematurely to form surface runoff and the rain is not fully infiltration.(6) Theslope Angle of impact on the test is not single, slope Angle, the greater the rainfallinfiltration, the more difficult the more not easy formation of critical slip surface, butthe greater the slope Angle, slope stability, the worse itself, the more prone toinstability.4. The phenomenon of typical landslide experiment is closely related to rainfalleffect. Research shows that:(1) Rainfall and surface runoff scouring fine particles tothe slope foot together and make the slope surface erosion.(2) Rainfall makes thesurface layer of gravel soil shear strength is reduced, in under the action of gravityappear local mud flow phenomenon.(3) Rainfall effect horizontal sliding downhillbody and settlement, due to different deformation degree of each part and make theslope cracks. |
PDF Full Text Request