Numerical Analysis On Behavior Of Geogrid-reinforced And Pile-supported Composite Foundation

When geogrid-reinforced and pile-supported composite foundation apply to foundation treatment engineering of factory buildings, we will always set a rigid ground on the surface. In this case, the behavior of composite foundation will be different from flexible ground foundation, such as high earth fill subgrade. This paper analysis the influence of ground stiffness and cushion on the behavior of geogrid-reinforced and pile-supported composite foundation.The main contents are as follows:(1) A3D numerical model is established using the finite element analysis software of ABAQUS, based on an indoor model test. Carry on the numerical simulation of settlement, pile-soil stress ratio, pile body stress distribution, and geogrid stress distribution, then Compare all the results with the results of model test.(2) Analysis the influence of ground stiffness on composite foundation, under the action of large area even load. The analysis result indicates, as the decrease of ground stiffness, the pile-soil stress ratio decrease, the surface uneven settlement and geogrid stress increase.(3) Analysis the influence of ground stiffness on composite foundation, under the action of locally concentrated load. The analysis result indicates, that as the decrease of ground stiffness, the pile-soil stress ratio decrease, differential settlement of pile and soil, the surface uneven settlement, horizontal displacement of pile and geogrid stress increase.(4) Analysis the influence of cushion under rigid ground floor. Analysis the influence of modulus of cushion material, cushion thickness, modulus of geogrid and reinforcement position on pile-soil stress ratio, settlement, pile body stress and ground stiffness. The result shows, the influence of cushion modulus and thickness on pile-soil stress ratio and settlement is significant. And when the geogrid is setted on pile top plane, it can play a good reinforcement effect.