Numerical Modeling Study On Portal Structure Anti-slide Piles Reinforcing Landslide

The portal structure anti-slide piles with larger lateral stiffness, can resist larger landslide thrust, and requires a lower resistance which anchored rock and soil provide, and can effectively control the deformation of the landslide, so plays a important role in the treatment of large-scale landslides. However, the portal structure anti-slide piles has complex structure, the mechanical mechanism has not yet fully understood, its designing method is still not unified, and the history of its practice is relatively short, so this treatment measure is lack of engineering practice experience. Therefore, the study on mechanical mechanism of portal structure anti-slide piles will have very good theoretical and practical significance. In this paper, based on the actual project, the force characteristics and the various factors of portal structure anti-slide piles is analyzed by the FEM, and finally some useful conclusions is obtained and can provide advice and reference in designing of portal structure anti-slide piles. In this paper, main researching work is as follows:(1) The existing method on calculating the remaining anti-slide force of landslide in front of anti-slide pile is analyzed, and the value of remaining anti-slide force by the existing method is proved larger, then a reasonable method is proposed in this paper.(2) By analyzing different single row pile numerical models, the discipline of landslide thrust taking on anti-slide pile and the variation of location of anti-slide pile is obtained, thus the selection principles on location of anti-slide pile is proposed.(3) By analyzing various numerical models with different row spacing,the discipline of row spacing and force characteristics of portal structure anti-slide piles is obtained, and then the reasonable range of row spacing is proposed.(4) By analyzing various numerical models with different stiffness of coupling beam, the discipline between stiffness of coupling beam and force characteristics of portal structure anti-slide piles as well as deformation of landslide is obtained. Furthermore, the comparison between non-coupling beam double row piles model with portal structure anti-slide piles demonstrates the advantages of the latter.(5) By analyzing the results of models with different row spacing,the discipline of pile-soil interaction is obtained, thus can be provided reference for the research of practical calculation model of portal structure anti-slide piles. And then, when the row spacing is small, the consideration that soil between double rows and below slip surface may become plastic state is needed, and can not be simply calculated using elastic foundation model.