Study On Pile-Soil Interaction And Design Calculation Method Of Serrated Anti Slide Pile For Steep Slope Landslide

Anti-slide pile is an important supporting structure for slope support and landslide treatment.Reasonable design and calculation method is directly related to landslide treatment effect and project cost.The slope with steep dip has a large dip angle,a great thrust force and a very high transformation of kinetic potential energy.Because of the obvious influence of the dip angle on the landslide thrust,the vertical effect of the landslide thrust was not fully considered in the anti-slide pile treatment in the past,the pile-soil interaction mechanism of landslide with steep slide surface can not be effectively revealed by using the post-thrust assumption theory,and there is a lack of a reasonable pile-soil interaction calculation model.Therefore,based on the study of the magnitude and distribution of landslide thrust,considering the interaction among the magnitude,distribution and mode of landslide thrust,the construction of a sawtooth anti-slide pile structure can improve the interaction between pile and soil,a structural model of anti-slide pile suitable for landslide with steep slide surface is proposed,and the calculating formula of saw-tooth anti-slide pile is derived,compared with the conventional anti-slide pile,the excellent anti-slide effect is proved,and the research results can provide a theoretical basis for further study and engineering practice of the sawtooth anti-slide pile:（1）the structure model of saw-tooth anti-slide pile is establishedBased on the spatial distribution of landslide thrust and the normal principle of landslide thrust and anti-slide pile force surface,the sawtooth-shaped anti-slide pile structure model is established.（2）the calculation model of sawtooth anti-slide pile is establishedBased on the interaction relationship between anti-slide pile and landslide thrust,two opposite torques produced by horizontal and vertical components of landslide thrust are considered to reduce the bending moment,shear force and displacement of anti-slide pile,based on the Winkler elastic theory,the pile-soil calculation model of sawtooth anti-slide pile is established.（3）study on mechanism of soil-soil interaction of sawtooth anti-slide pileIn this paper,the relationship between the internal force and deformation of saw-tooth anti-slide pile and the dip angle of slide surface,the size and number of force components of anti-slide pile,the effective length of cantilever section and anchor section,and the size of pile section is analyzed theoretically,based on the vertical analysis,the self-weight of anti-slide pile,the friction resistance around the pile and the action of the pile bottom,the boundary conditions of the anchorage section of the saw-tooth anti-slide pile are established.（4）seismic performance analysis of saw-tooth anti-slide pileA slope model of saw-tooth anti-slide pile is established by using FLAC_3Dsoftware,and the dynamic response of saw-tooth anti-slide pile is analyzed under seismic condition,and compared with that of common anti-slide pile under the same working condition.（5）design theory of sawtooth anti-slide pileBased on the study of pile-soil interaction of anti-slide pile,it is considered that the calculation of horizontal thrust of anti-slide pile should include the residual slide force behind the pile and the resultant force of the residual anti-slide force before the pile in the horizontal direction,the normal equilibrium equation of sliver slide surface and the normal equilibrium equation of sliver slide surface are established.Considering the soil arching effect,the calculation model is established according to the two types of action of soil arching behind piles and between piles and soil arching behind piles,and the calculation theory of anti-slide pile structure size is obtained.