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

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.