论文部分内容阅读
桩基础沉降计算理论在国内应用较多的是Geddes应力法,目前在应用Geddes解计算桩基础沉降时,一般不考虑筏板刚度的影响,假定所有桩均分上部荷载,理论上存在缺陷。为了使桩筏基础的沉降计算更加合理,本文将薄板理论与Geddes解结合在一起,提出分析桩筏基础的新方法。该方法采用Kirchhoff薄板理论模拟基础底板,土被当成各向同性弹性半空间体,桩与桩之间以及桩土之间的相互作用通过Geddes解实现,采用有限单元法计算出每根桩分担的荷载,据此桩顶荷载,根据Geddes解计算桩基沉降。本方法解决了桩基沉降计算理论上的不足,使计算原理和计算结果更加合理。同时,在有限元计算中,采用对角阵近似代替群桩的满秩刚度矩阵,使计算时间大大缩短,能够分析较大规模的桩筏基础。
The calculation theory of pile foundation settlement is mostly applied in China by Geddes stress method. At present, when Geddes solution is used to calculate the settlement of pile foundation, the influence of raft stiffness is generally not considered, and all the piles are equally divided into upper loads, theoretically there are defects. In order to make the settlement calculation of piled raft foundation more reasonable, this paper combines the theory of sheet metal with Geddes solution and proposes a new method of analyzing piled raft foundation. In this method, Kirchhoff plate theory is used to simulate the foundation slab. Soil is treated as an isotropic elastic half-space. The interaction between pile and pile and between soil and pile is realized by Geddes solution. The finite element method is used to calculate the share of each pile According to the pile top load, pile foundation settlement is calculated according to Geddes solution. The method solves the theoretical deficiencies of pile foundation settlement calculation and makes the calculation principle and calculation result more reasonable. At the same time, in the finite element calculation, the diagonal matrix is used to replace the full-rank stiffness matrix of pile groups, so that the calculation time is greatly shortened, and the larger-scale pile-raft foundation can be analyzed.