Abstract:In recent years, inclined pile groups have been widely used in the construction of wharf and bridge foundation to resist lateral load, while its vertical bearing characteristics also attract the attention of researchers. How to evaluate the vertical bearing characteristics and pile effect of inclined pile groups is important in engineering. In this paper, combined with the pile foundation selection project of Hanjiang Bridge on Xiamen-Shenzhen passenger dedicated railway line, five kinds of pile spacing analysis models are established for the pile group foundation with inclination angle of 0 °～12 °, and the bearing characteristics and pile group effect are simulated and analyzed by finite element method. The results show that in terms of vertical bearing characteristics of pile foundation with different distance from group, the most reasonable inclination angle is about 8°. The load-settlement curve of vertical pile foundation is slow variant and the inclined pile foundation is steep variant. The settlement decreases suddenly when the pile spacing reaches 4 times of the diameter of the pile, and the sudden decrease value of vertical pile foundation is larger than that of inclined pile foundation. The influence range of soil deformation field of inclined pile base is larger than that of vertical pile foundation. With the increase of load and pile spacing, the vertical deformation of soil between piles decreases significantly, the clamping effect of soil between piles weakens, and the friction resistance of upper part of pile side increases gradually under the action of stress. The axial force of vertical pile group has the property of angular pile > side pile > middle pile, and the axial force of inclined pile group has medium pile > angle pile > side pile, whereas the change rate of axial force increases with the increase of pile spacing. The load sharing at the top of the pile tends to be uniform with the increase of the inclination angle and pile spacing of the pile group, and the effect coefficient of the vertical pile group increases rapidly before the pile spacing is 4 times of the pile diameter, and slows down after 4 times of the pile diameter. When the vertical pile spacing is 5 times of the pile diameter, the pile group effect coefficient is stable, and the inclined pile foundation is stable when the pile diameter is 6 times, and the pile group effect coefficient of 8° inclined pile foundation is the largest under different pile spacing.