Study On The Creep Mechanism And Stability Of Soil Slope

Under the action of kinds of influence factors, soil slope could occur creep deformationwith time. The stability of soil slope may reduce, and creep deformation of soil slope mayincrease, especially with the influence of groundwater and soil strength degradation. Acertain degree of creep deformation of soil slope could lead to slope failure. Therefore,the research on creep behaviors and characteristics of soil slope, the creep model of soilslope and the reduction of the soil slope stability with time has important theoretical andpractical significance in creep slope treatment.Taking a creep soil slope in Fujian province as an example, based on engineeringgeological conditions of the slope and physical and mechanical parameters of various soillayers obtained from laboratory tests, on the basis of the dynamic displacement rule of thecreep slope from monitoring data in the field, this thesis emphatically analyses the actionof soil strength degradation and groundwater on slope creep sliding deformation，using thenumerical analysis model with the limit equilibrium principle and finite the elementtechnique which are used to calculate displacement of slope soil.This thesis mainly get the following conclusion:(1) Groundwater has various effect on the stability of the creep slope. Groundwater,which damps soil slope makes the combination of soil particles weakened, resulting inreducing the soil shear strength in sliding zone could soften the soil，lower soil strength andcause and aggravate slope slide with lubricating the sliding surface. The rise ofgroundwater level increases static water pressure, dynamic water pressure, whichintensifies creep deformation and gives rise to the slope failure finally. With the rise ofgroundwater lever, the coefficient slope stability decreases with a quadratic functionapproximately.(2) With time and the influence of underground water level, the soil shear strengthcould be more and more low. In the case of degradation of soil strength, creep deformationof soil slope may significantly increase. After the instantaneous elastic deformation andcreep deformation takes place, the displacement of soil slope could be basically lineargrowth with time, namely the constant velocity growth stage of the deformation that the velocity of creep deformation is relatively steady in the process.(3) The safety factor of soil slope, obtained from the limit equilibrium analysisprinciple, is inclined to be large, without considering that creep deformation decrease thesafety factor. The above situation has a certain disadvantages on evaluating the long-termstability of soil slope. So, studying behaviors of slope creep is one of the ways to solve thisproblem.(4) Soft soil creep model used in this article can better simulate the elastic stage, initialcreep stage and steady creep soil stage of slope deformation under low stress. It providessome reference for evaluation of the long-term stability of soil slope. The combination withthe limit equilibrium analysis theory and creep deformation time shall assess the slopestability synthetically.