The Finite Element Analysis Of Soil-pile Raft-superstructurea Considering Contact Effect

Pile-raft foundation is widely applied in high-rise buildings in practice, which has theadvantages of pile foundation, high bearing capacity, reducing settlement, but also has the raftfoundation can adjust uneven settlement, to expand the use of underground space. Theconventional design in general the upper structure, pile raft foundation, respectively, onlyconsidering the force equilibrium conditions, but in actual engineering, the interactionbetween the three, existing displacement equilibrium, resulting from the distribution ofinternal force of the structure. Pile raft foundation and soil of different materials, there is acontact at the interface, work character of contact analysis can reflect the real soil and pile,raft and soil.This article consists of theoretical analysis and finite element analysis. Access on thebasis of a large number of domestic and foreign literature and experimental data, summarizesthe constitutive relationship of soil, pile-soil interface development, design considerations anddoes not consider the combined effect of soil-pile raft-the model of the upper structure,useing ANSYS finite element analysis software for modeling and analysis,. The conclusionsare as follows:（1）When considering the interaction, Side column are loading,Middle column areunloading, bending and shear beam interaction considered, significant changes;（2） When considering the interaction, the uneven settlement of the upper structurecan regulate the raft, but has little effect on the average settlement; for the raft moment,conventional design even more than the combined action;（3）Considering the interaction, settlement difference between piles is lower than thatwithout considering the interaction;（4）When change the stifiness of the upper structure, pile raft foundation and soil, thethree part of internal force and deformation also change.