This paper has deduced the effected diameter of a closed large diameter pipe pile on sand ground as well as the horizontal resistance （or moment） acting on the rigid large diameter pipe pile. And

it provides the theoretically optimal design for the similar case; and by using the MATLAB program to analyze the axial stiffness of single pile

the relationships of stiffness of single pile

and the equivalent stiffness modulus of the soil beside the pile for unit depth

the equivalent stiffness modulus of the soil at the bottom of the pile

the thickness of the steel pipe pile

as well as its diameter

length and the elastic modulus for the used material are now much more clear. Based on this idea

the corresponding axial force can be calculated by using the load transfer hyperbolic function for known or assumed compressive deformation of the pile body.