Studies On The Landslide Progressive Destruction Model Based On Displacement Analysis

China is a country of frequent geological disasters, especially since 1980 s, with the rapid development of economic construction and the impact of natural factors, landslide,debris flow and other geological disasters are increasing year by year.The existing methods of slope stability analysis are based on the limit equilibrium theory, which can not consider the progressive failure process of the slope. Anti-slide pile, especially the anchored anti-slide pile, is an effective supporting structure for the treatment of large landslide,but the working mechanism and calculation method of anti-slide pile is still need to be further studied.Based on the research ideas of that collecting and reading the literature firstly, then doing numerical simulation and theoretical model, finally analyzing the data, with“a main line, two focus” to carry out the study in this paper.After depth research on the progressive failure model of landslide based on displacement analysis and the calculation model of anchored stabilizing piles based on displacement of soil around pile, the following innovative achievements are obtained:1 To consider the impact of displacement factor on the progressive development of landslide, a new simplified method that can consider the relationship between shear stress and shear displacement of sliding face is presented to evaluate the stability of a landslide by using of a sliding surface t-D constitutive model. The formula of the simplified method are derived and their algorithm is programmed by Matlab code.2 Starting from the original meaning of safety factor, this article puts forward the definition of the partial safety factor and divides the different points on the sliding surface into stable, sub stable, unstable three states. Meanwhile this method can also effectively simulate the slope development process from the beginning to the final sliding surface penetrating, has realized the quantitative correspondence relationship between displacement and safety factor, so as to achieving function of the slope stability forecast.3 This paper saw whole pile as a beam on elastic foundation, a two-stage pile-soil interaction mechanics control equations based on displacement method was established. The mathematics analytic solution of control equations were obtained by initial parameter method. Matlab computing program was compiled for the calculation of internal forces and displacements.Using the above research results, combined with numerical simulation, modelexperiment and engineering examples, the following conclusion were drawn:1 The stability factor with strain-softening behavior depends not only on the strength parameters but also on the shear stress-shear displacement relationship of soil,and it is unsafe for the limit equilibrium method to be applied to practical engineering.2 This paper presents a progressive failure model of thrust-type landslide, that in the process of deformation and failure the trailing edge of the landslide is often in a state of destruction and the leading edge of the landslide is often in a state of pre-peak stress,thus along the sliding surface can be divided into : unstable region,critical region,stable region, and with the accumulation of deformation, critical region slowly move forward.3 The empirical method that the choose of landslide thrust distribution only depend on the rock and soil properties behind the pile is unreasonable. In the design, it should also take into account the impact of initial tension, anchor stiffness, anchor position, and the initial tension, the anchor stiffness will cause the increase of the landslide thrust.4 Under the effect of huge anchor tension, the piles bend to the slope and produce active supporting force, meanwhile produce a significance reverse bending moment,and these are not to be ignored in the anti-slide pile design.5 The landslide thrust acting on the supporting structure no longer follow the limit equilibrium theory, but consider the landslide progressive failure process, and closely related to the initial anchor tension, the stiffness of anti-slide pile and anchor,rock physical properties and other factors.6 The distribution of landslide thrust has a great influence on the pile bending moment, and it is difficult to grasp in the design and calculation of anchored pile. The calculation method of pile based on the displacement of soil do not need to assume the distribution of the thrust and depend entirely on pile-soil-anchor interaction to adjust the distribution of landslide thrust.