Three-Dimensioned Numerical Analysis Of Rigid Pile Composite Foundation Under Lateral Loads

Rigid pile composite foundation is an artificial foundation in which concrete piles with high stiffness or CFG piles with high grade are used to enhance the vertical carrying capacity. By laying the cushion layer, the stress of the soil between the piles is adjusted to be balanced, thus decreasing the stress concentration at the bottom, providing a method of making full use of the soil's potential and saving the cost the project. So, it has been widely used at present.At present, the theoretical research on rigid pile composite foundation is far from systematic. In contrast, the numerical analysis is an efficient way to study them. The existing numerical analysis in studying the composite foundation is two-dimensional analysis under consumption of plain-strain or simple three-dimensional analysis in single pile. For pile group, the three-dimensional analysis is more complicated, and thus reference data is quite few.In this paper, finite element analysis software ANSYS as a tool, through the establishment of rigid pile composite foundation pile three-dimensional nonlinear finite element model of rigid piles under horizontal load bearing capacity of composite foundation level characteristics analyzed.Studies have shown that:(1) in the rigid pile composite foundation, due to the presence of cushion, can greatly improve their level of pile bearing capacity.(2) The thickness of cushion a direct impact on the level of rigid pile composite foundation bearing capacity characteristics, too large or too small cushion thickness will increase the rigidity of pile bending moment and deflection is not conducive to the safety of pile should be a reasonable choice mattress cushion thickness, available from this calculation, the thickness of the cushion should take 200～300 mm is appropriate.(3) Horizontal loads may have broken the location of piles and the pile length is only relevant, but has nothing to do with the pile diameter, so be sure to cut off the pile did not occur in 3.5D Department, but in 0.175L (L is pile length).(4) Horizontal load for the pile displacement effects, larger than 0.175L,0.175L following the relatively small...