筒体-桩筏-地基土共同作用非线性数值分析

考虑上部结构、基础与地基土三者共同作用,以及土的弹塑性性质,采用中厚板理论分析筏板,建立了全三维有限元模型,对筒体结构下桩筏基础受力作了非线性数值分析。通过对弹性模型和弹塑性模型计算结果的比较,明确了非线性分析的意义。研究了地基土应力、应变随荷载的变化情况及桩顶反力分布的发展过程,并指出筏板厚度的增加并不总是使桩顶反力趋于不均匀。同时,讨论了土塑性及基础沉降曲面形状对桩筏基础工作性状的影响。

Non-linear Numerical Analysis of Interaction among Pile-raft Foundation Tube Structure and Soil

Considering the interaction among upper structure,foundation and soil,also taking the elastoplastic property of soil into account, analysis of raft based on the medium-thickness plate theory, the three dimensional finite element model is established, and numerical analysis is used to study the internal force of pile-raft foundation below tube structure. Comparison between elastic model results and elastoplastic model results is made. Significance of non-linear analysis is demonstrated. Chang rule of soil stress and strain along with load increment is studied. Development of pile reaction force distribution is investigated. It is pointed out the trend of pile reaction force is not always becoming non-uniform with the increase of raft thickness. In the meanwhile, the influence factors of pile-raft foundation behavior such as elastoplastic property of soil and settlement surface of foundation are discussed.