| As a kind of non-continuous retaining structure,anti slide pile could achieve continuous retaining function by the soil arching and itself.According to the different construction technology,the pile body has a rectangular,circular and other forms of cross-section.The rectangular pile has the advantages of simple cross section and good mechanical properties.In recent years,with the increased requirements of construction efficiency and machinery properties;the widespread use of mechanical hole forming technology make circular anti slide pile beginning to be used.However circular anti slide pile's mechanism of force deformation characteristic and soil-pile interaction is still not clear.In summarizing and analyzing the theory of existing pile-soil interaction and its relevant experiment or numerical simulation results,the same bending stiffness of rectangular and circular anti slide piles have been used for geotechnical centrifugal model test to compare the load response and pile-soil load transmission characteristics difference between the two kind of piles.Through the two-dimensional granular flow numerical simulation analysis,the influence of pile spacing,soil-pile bearing capacity,soil arching effect and pile-soil load share ratio were discussed,conclusions can be drawn as the followed:(1)In geotechnical centrifuge model test,along with the enlargement of landslide thrust,the displacement of soil between rectangular piles of soil is smaller than the circular pile's.Soil between piles was early shattered after the overall massive flaking forming soil arch,depending on the soil and the pile soil surface formed at the arch foot,stripping off the pile the soil is massive,and a smooth side of the narrow width obtrapezoid;circular pile surrounding soil is whole moving rectangular pile,the soil between piles is large and scattered flaking,the pile of soil along the pile side flow phenomenon,soil arching phenomenon is relatively obvious.(2)Through different kind of sensors test in the centrifugal field loading landslide thrust,the displacement at the top of circular pile is about 71%?91%equal bending stiffness of rectangular pile.The proportion of maximum displacement at the top of pile and the cantilever length were 4.1 per thousand and 4.5 per thousand between the two kinds of piles respectively.Both thrust and bending moment along the cantilever section remain a shape of trapezoidal distribution.Circular pile's landslide thrust at the same height is approximately rectangular pile's 44%?98%;bending moment about rectangular pile's 43%?114%.(3)In the simulation of particle flow code,with the increasement of loading wall displacement,the soil stress is concentrated before the pile,and the soil between the piles is supported by the pile side friction.Rectangular pile soil between the whole extrusion but not flowed.With pile spacing increasing,soil arching height decreased,and the pile bearing ratio increased.The soil flowed around the circular pile and prone to load deviation.Soil arch had little influence on the ratio of load sharing.(4)In the calculation model,with the increasement of loading wall displacement,the total load of pile and soil and the resistance to sliding force of each pile reach the peak value,and the load on soil arching assumes an upward trend.The maximum bearing capacity of rectangular piles decreases rapidly when the net distance ratio between piles is 1.5?3.0,and gradually decreases at 3.0?4.0,then decreases rapidly,and the model of circular piles shows a slow downward trend.When the ratio of net clearance between the same piles,the total bearing capacity of the round pile is about 83%?98%of the rectangular pile,while the load sharing ratio of the round pile is 92%?97%of the rectangular pile,and the difference between the two piles decreases with the increase of the net spacing ratio between the piles. |
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