Study On The Vertical Displacement Direction Rate Of Colluvial Slope And Its Evolution Feature Of Stability

Slope is a kind of geological body with a certain height and gradient. It is ageomorphic form and the geological engineering, which distributes in the surface ofearth widely, and is the most common and most basic natural environment form inhuman survival and engineering activity. The failure of slope can cause seriouslythreatens to human life and production. In all forms of slopes, the landslide is the mostwidely distributed, the most serious.. And the proportion of colluvial landslides in alllandslide is fairly large. Colluvial landslides, which includes all of the soil layerlandslides, the accumulation landslides in mountainous district, and the looseaccumulation landslides caused by constructing, unloading and weathering take place inthe Quaternary System and recent loose accumulation,and it is widely distributed inChina. Supported by the projects of National Natural Science Foundation of China andselecting Huang Lashi landslide in Ba Dong county in the Three Gorge reservoir regionof the Yangzi River as the example, the thesis has carried out a study on the verticaldisplacement direction rate, displacement, displacement rate and plastic zone of theslope by means of the numerical simulation software—FLAC3D. Some results aresummarized as follows:1. It is found that gravity and complex water environment factors are the majorrevival factors of debris landslides by analysis of the basic features and dynamicdisplacement features of debris landslides.2. It is found that one single parameter displacement or displacement velocity isnot enough to evaluate dynamic evolution behavior and the slope failure. The verticaldisplacement direction rate, an important displacement parameter of the displacementvector field, is a different from displacement or displacement velocity in dynamicproperty.3. In this paper, the soil plasticity mechanics theory, combined with the slopecharacteristics, is used in the study and put forward the characteristics of the verticaldisplacement direction rate in the slope deformation stage. The change of the verticaldisplacement direction rate reflects the change of stress field and the displacement’sadjustment in evolution of slope stability, which can be used to determine the conditionof force in the evaluation of dynamic evolution behavior and the slope failure.4. The time-space changing law of the vertical displacement direction rate in different stability stage is studied by means of numerical simulation software—FLAC3D. It is found that the vertical displacement direction rate in differentpositions of colluvial slope is changing with the decline of safety coefficient thoughtheir characters are different. The sharp drop or rise of the vertical displacementdirection rate will take place when the slope reaches the critical state of stability. Thisfeature can be chosen as the criterion of evaluating the slope stability.5. In this thesis, the time-process curves of the displacement, displacement rateand the vertical displacement direction rate of this monitoring points on the leadingedge were compared and analyzed, especially time-process curves of displacement andthe vertical displacement direction rate are analyzed in different fold reduction. So wecould find that the vertical direction rate in the evaluation of landslide stability is moreprecise.