The foundation of the dock yard is usually relatively weak.When there are important buildings (structures) near the yard,in order to ensure the structural safety of the buildings,it is necessary to evaluate the effect of large-area loading on the mechanical properties of the adjacent foundation piles,mainly including the displacement of the foundation piles and the internal force of the pile body.However,the current regulations do not specify this.This article uses the classic Boussinesq stress displacement solution as the basis to derive a method for calculating the soil displacement and stress under arbitrary load,and develops corresponding calculation programs.The displacement and stress of soil are used to indirectly calculate the deformation and internal force of pile body.Taking a coal shed project as an example,the above method is used to calculate the displacement of the pile top and the internal force of the pile body under the coal pile loads.The results show that the maximum lateral displacement of the foundation pile met the requirements of the specifications,and the axial force and bending moment of the pile body are relatively large.The strength calculation of the pile body should consider the internal force of the pile body generated by the above loads.The use of this calculation method can conveniently calculate the displacement and internal force of foundation piles under any load,and the calculation is more accurate,which can provide reference for similar projects.