上部结构-桩筏基础-地基相互作用有限元分析

为了研究结构-桩-土的相互作用,利用有限元程序对上部结构-桩筏基础-地基相互作用体系建立了三维有限元分析模型.通过计算分析并与常规设计作了比较,对两种情况下上部结构的内力变化作了探讨.结果表明:筏板发生"盆型"变形,上部结构的梁、柱内力都发生了重分布:即四个角柱轴力增大,边柱和内部柱都出现卸荷现象;柱端弯矩最大值和梁端弯矩最大值都出现在最底层.计算中土体、桩、筏、结构等材料都取弹性范围分析.

Finite Element Analysis of Interaction of Upper Structure, Pile Raft Foundation and Soil

In order to study the interaction of upper structure,pile raft foundation and soil,a modle of three dimensional finite element analysis is established.A general purpose finite elements program is adopted in the computation.The internal force change in upper structure is investigated using conventional method and interactional analysis method.The analysis results indicate that the displacement distribution of the raft looks like a dish,the internal force distribution of columniations and beams is different,the axial force of four corner columniations increases while the axial force of border columniations and interior columniations reduces,the maximum bending moment of the columniations and beams appears on the ground floor.For computational analysis,deformation of soil,pile,raft and structure are all in elastic range.