Model Test on Vertical Capacity of Inclined Pile Groups with Center Pile in Layered Strata

The study of inclined pile groups with center pile is new and important for development of pile foundation. This paper presents that model tests about inclined pile groups with center pile have been conducted considering the different inclination of pile. The results show that the settlement curve of vertical pile groups presents gradual while that of inclined pile groups presents steep. There exists an optimal inclination to increase the vertical bearing capacity for inclined pile groups, which is located between 8°∼12°. In vertical pile groups, the distributing rules of axial force at the same depth are as follows: the biggest is the corner pile, next is the side pile, and the smallest is the center pile; but in inclined pile groups, the biggest is the center pile and the smallest is the side pile.