Characteristics of negative skin resistance and settlements at center of annular pile groups under filling load

Sphere site is a large area filling on deep soft subsoil. All spheres are supported by annular pile groups which are end bearing and long bored piles. The settlement value at the center of pile groups is less than that at the outside of the pile groups, which reflects the influence of negative skin resistance to the surrounding soils of piles. By simulating the soil settlement characteristics at the center and outside of pile groups, the characteristics of negative skin resistance of the pile groups are analyzed and compared with the results calculated by the present code. Some useful conclusions are drawn for calculating the negative skin resistance.