分层地基模型|桩筏基础|沉降|非线性|离心模型试验

基于改进的分层地基模型,考虑桩–土–筏的共同作用,提出了刚性桩筏基础非线性分析方法。地基附加应力计算考虑土层参数的变化,采用层状弹性体系的Burmister应力解;地基变形采用分层总和法,所采用的计算参数压缩模量和一维回弹模量试验确定方便。通过简单的室内一维加卸载试验确定其随加卸载次数的变化,进一步得到桩筏基础在重复加卸载下的沉降规律。对单桩和桩筏基础进行离心模型试验,并将计算结果和试验结果进行对比分析,验证了本文方法的正确性,可应用于实际工程问题的分析。

Analysis on settlement of piled raft foundations under repeated loading and verification by centrifugal model tests

Based on an improved layered foundation model,the interaction of piles-soil-raft is taken into account to formulate a nonlinear method for the analysis of piled raft foundations.Considering the variation of layered soil properties,the Burmister stress solution of multilayered elastic half-space is applied to calculate the additional stress in soils and the layer-wise summation method is used to calculate the settlement of soils.An analysis method for predicting the settlement of piled raft foundations under repeated loading is then proposed by employing soil parameters of one-dimensional compression modulus and one-dimensional resilient modulus,which can be easily determined from one-dimensional loading and unloading laboratory tests.Centrifugal model tests are performed to examine the load transfer character of a single pile and the settlement of a piled raft foundation.A comparison between experimental and calculated results is carried out,and the correctness of the proposed method is validated.