Research On Stability Analysis And Support Parameter Optimization Of Expansive Soil Cutting High Slope

With the rapid development of national economy and transportation industry,the construction of expressway is developing from the city to the remote mountainou areas,the stability problem of cutting slope will be encountered undoubtedly.Expansive soil has the characteristics of swell shrink,crack and strength attenuation,which lead to the expansive soil slope landslide.According to the special engineering properties of expansive soil,the landslide mechanism of expansive soil cutting slope is analyzed.Taking expansive soil cutting slope of Wanyi highway in Jiangxi Province as the engineering background,the stability of expansive soil cutting slope under the action of anchor frame beam is analyzed.Meanwhile,the support parameters optimization is analyzed.Finally,the stability of expansive soil slope under the coupling action of rainfall and cracks is anlyzed.The main work of this paper as follows:1.The landslide mechanism and characteristics of expansive soil slope is analyzed.By summarizing the research on the mechanism of the expansive soil slope at home and abroad,it is found that the generation and development of the cracks are the key factors to influence the expansive soil slope landslide.The landslide characteristics and the applicability of reinforcement measures of expansive soil slope are summarized.2.The Stress of soil slope which is reinforced by anchor frame beam are analyzed.The differential expression of the displacement and axial force of anchor is established based on the interface soft-slip mechanics model,and the analytical solution of the equation is obtained by mathematical deduction.According to the method of building foundation,three kinds of calculation models for calculating the internal force of frame beam are considered,and the basic theory and deficiency of each model are expounded.3.Mechanical parameter test of expansive soil in slope engineering.By obtaining soil in situ of Wanyi expressway A2 contract section of expansive soil cutting slope and taking the indoor test of triaxial shear test,triaxial permeability test and so on,some mechanical parameters of expansive soil are obtained4.Research on the stability of expansive soil cutting slope under anchor frame beam reinforcement and support parameter optimization.By using the finite difference numerical simulation method to calculate the stability of expansive soil cutting multistage slope under the action of anchor frame beam,and the anchor frame beam supporting parameters(such as anchor spacing,length and layout angle)are analyzed,it is can provide theoretical basis for engineering design.5.Stability analysis of expansive soil slope under the coupling action of rainfall and cracks.By using the finite element analysis(seep/w)and limit equilibrium analysis(slope/w),the seepage field change and slope stability of expansive soil slope under the coupling action of rainfall and cracks are analyzed.Meanwhile,the stability of expansive soil cutting slope under the anchor suppoting are evaluated,and the reliability of anchor supporting expansive soil slope is verified.