SETTLEMENT CALCULATION OF PILE GROUPS BY LOAD TRANSFER METHOD

Settlement calculation is one of the key problems that can not be neglected in the design of pile foundations.Based on the shear deformation transfer method,the settlement characteristics of pile foundations is analyzed,and the displacement fields in the surrounding soil of each pile in the group caused by shaft resistance are obtained.The displacement fields are modified by considering the reduction effect caused by the existence of piles.Superimposing the displacement fields in the surrounding soil of each pile in the group,the equivalent stiffness coefficients of unit thickness of soil around each pile are developed,taking into account the interaction among the piles.The Boussinesq solution is modified to include the effect of different embedded depths and then used to derive the equivalent stiffness coefficients of the soil under the pile tips.A method to calculate the settlement of pile groups is then established based on the load transfer method.Settlement predicted by the present method agrees well with those measured from the model test of pile foundations.