复合桩基地基土中附加应力分布特征及沉降计算简化方法

RESEARCH ON THE SOIL ADDITIONAL STRESS AND SIMPLIFIED SETTLEMENT CALCULATION OF COMPOSITE PILE FOUNDATION

利用有限单元法模拟分析了复合桩基在竖向均布荷载作用下的工作状态,经与常规桩基的计算结果分析对比,并结合有关试验结果以及经典的Boussinesq解答,得出了复合桩基地基土中附加应力的分布特征和变形规律。复合桩基桩间土存在较大的附加应力,并且沿桩身分布较为均匀,桩间土存在压缩变形,复合桩基沉降计算应同时考虑桩间土和桩端以下土体的压缩,最后提出了复合桩基沉降计算的简化方法并应用到工程实例计算中。

The working condition of a composite pile foundation under vertical and uniform loads is simulated by finite element method.With some experiment results and classical solution of Boussinesq,the behavior of distribution of additional stress and deformation in the composite pile foundation is concluded by comparing with the calculated results of common pile foundation.Biggish additional stress exits in the soil between the piles and the stress is distributed equally along the pile shaft.There is a certain compression in the soil between the piles,which must be considered in the composite pile foundation settlement calculation as well as that under the pile bottom.In the end,a simple calculated method is presented and also applied to projects.