The X-section cast-in-place concrete pile (XCC pile) is a new shaped pile. The pile-soil interactions are influenced by the cross-sectional geometry. The load transfer mechanism of the XCC pile dependent on the cross-sectional geometry has been derived by means of equilibrium analysis. However

the mechanical response of the vertical shearing coefficient

governing the pile-soil interactions

for the cross-sectional geometry have not been fully understood. This paper represents the effects of the three geometrical parameters (the diameter of the surrounding circle R

the distance between two adjacent cutting circulars 2a and the central angle of the cutting circle ?X) of the X-shaped cross-section on the vertical shearing coefficient. Comparative analyses between the XCC pile and circular pile of the same cross-sectional area are carried out. It is found that the pile-soil interactions vary with the changes of the geometrical parameters. Influenced by the cross-sectional area

the pile parameter and the vertical sharing coefficient

the axial force increases with the increasing of R and ?x

but decreases with the increasing of 2a. In addition

the axial force of XCC piles is always smaller than that of circular piles of the same cross-sectional area.