A Y-shape pile is a newly-developed abnormal pile with a reversed-arch surface. The tip resistance distribution along the pile bottom section is non-uniform. Although the calculated additional stresses, due to the assumed uniformly distributed tip resistance, is more close to the actual values compared to those due to the assumed concentrated tip resistance, the former still has some error. Based on the numerical simulation, the nonuniform distribution model of tip resistance for a Y-shape pile is developed, and used to calculate the additional stresses. By means of the integral function NIntegrate of Mathematica software and Geddes's stress solution, the numerical calculation method is introduced to estimate the vertical additional stress coefficient at any point in foundation under the action of tip resistance of Y-shape pile with considering the effect of abnormality. Assuming the major factors as variables, including the outside circle radius R, template radian., open arc spacing s, and angle radian., the variation of additional stress is comparatively studied for two distribution patterns of tip resistance of the Y-section pile, i.e, the uniform distribution and the nonuniform distribution with considering abnormality effect, respectively, and the method for calculating the additional stress due to tip resistance is used for estimating the settlement with considering abnormality effect. Based on the field static load tests, it is found that the calculated settlements agree well with the measured results using the proposed method.
