考虑固结过程的桩-土-筏三维相互作用分析

针对存在较厚软弱下卧层的桩土筏结构体系 ,本文建立了桩端下卧层固结沉降计算的半透水边界模型。应用半透水地基固结解得到任一时刻桩端下卧层的沉降 ,进而得到任一时刻群桩中每根单桩的刚度。与筏板有限元分析结合 ,构成桩 -土 -筏共同作用有限元分析模型 ,并研制开发了相应的分析软件 ,可以分析筏板内力、筏板挠度和桩顶反力随时间的变化规律。工程分析表明 ,此方法有一定的实用价值

3D interaction analysis of pile-soil-raft considering the consolidation of substratum

A new calculating model for the consolidation settlement of piles group was built by approximately simulating the stress and permeability field of vertically loaded piled raft foundation. The effective and total stress in substratum at any time was obtained by applying the consolidation solutions with impeded boundaries.The settlement of pile tip can be evaluated by layerwise summation method. Thus the stiffness of single pile in pile groups can be obtained at any time.Then it is agglomerated to the raft,and the raft was analyzed by finite element method.A software for analyzing the pile-soil-raft interaction was developed. The development of internal force, deformation of raft and reaction on top of pile can be gained. One case study was also carried out to show the application of the present method to practical pile group problems.