The Mechanical Characteristics And Optimization Design Of Pile-Slab Structure Subgrade In The Landsilde Body

It focus on the stress characteristics of pile-slab structure subgrade in the landslide body, and study on synergistic mechanism of bearing force of pile-slab structure subgrade and anti-slide piles in the case of the increasing residual landslide thrust. The main findings are as follows:1. The research on the stress characteristics of pier-pillar pile-slab structure, bearing bridge pile-slab structure and buried pile-slab structure in the landslide body and the analysis of the applicability of the three types of pile-slab structure subgrade with the structure theory analysis. The stress of buried pile-slab structure is more reasonable than the bearing bridge pile-slab structure and the pier-pillar pile-slab structure. But because of the buried pile-slab structure roadbed bears stress much larger than the other two under the same loads and it should be considered on the large cost of graded broken stone when this structure is used in a wide range. The internal force value of bearing bridge pile-slab structure and buried pile-slab structure have little difference and the bearing bridge pile-slab structure has fast construction, less material consumption, low cost. Therefore a wide range of use pile-slab structure in the landslide body, it is recommended should first consider the use of the bearing bridge pile-slab structure.2. Study on numerical simulation of the three types of pile-slab structure in the landslide body by the large finite element software ABAQUS. The stress of buried pile-slab structure is more reasonable than the bearing bridge pile-slab structure and the pier-pillar pile-slab structure in the numerical analysis. The result is consistent with the findings of the structure theory analysis.3. Study on the influence of the relative position of the pile-slab structure subgrade and the anti-slide piles, and the stress of the pile-slab structure subgrade in the case of the increasing residual landslide thrust by the finite element software ABAQUS. The results show that when the pile-slab structure subgrade is set up after the completion of the landslide treatment, it bears a small landslide thrust and doesn’t affect the stability of the line. If the residual landslide thrust increase after the completion of the project, the pile-slab structure subgrade and anti-slide piles bear the thrust force together, and the pile-slab structure set in front of anti-slide pile bears less landslide thrust and the security is higher than that set in the anti-slide piles behind. Because it’s inevitable that the pile-slab structure subgrade bears a certain landslide thrust, we should give some consideration to the effect of landslide thrust on the pile-slab structure subgrade in the design from the point of the reliability.4. A finite element model was set up by taking landslide treatment scheme and the design information of pile-slab structure of Gui-Guang line through the PingZhai landslide area as a reference object. Study on the optimization design of the pile-slab structure subgrade and the anti-slide piles by the finite element software ABAQUS. The results show that if the residual landslide thrust increase after the completion of the project, the pile-slab structure subgrade and anti-slide piles bear the thrust force together, and the location of the three-row stabilizing piles are optimum and remove any one row anti-slide piles will affect the stability of the pile-slab structure; the embedded depth of pile-slab structure pile have little effect on the pile top horizontal displacement with the embedded depth of pile-slab structure pile begins to increase from1.4m.