Numerical Analyses On The Behavior Of Horizontally Loaded Batter Piles

Batter piles are increasing widely used in practice such as bridges, docks, offshore drilling platform and large transmission towers engineering, due to its good level of horizontal bearing capacity. Batter piles axis is not perpendicular to the ground and the initial stress field of surrounding soil is no longer axial symmetry, which make its behavior is much more complex. So it has an important practical significance to engineering. FEM method was utilized to simulate the response of single batter piles and transmission tower batter pile group under horizontal load, the main works and obtained achievements in this paper are as follows:1. The numerical model of free-head single batter pile is established. The influence of pile shaft inclined angle and vertical load applied on the pile head on horizontal displacement, bending moment and shear force of batter pile was investigated. The compression and shear interaction between the pile and surrounding soil were explored. And the effective length of batter pile when subjected to horizontal load was also discussed. The results show that the horizontal bearing capacity of vertical pile is less than that of the positive inclined pile, but greater than that of the negative inclined pile. The horizontal displacement, bending moment and shear force of batter piles are significantly influenced by the shaft inclined angle. It was found that the vertical load acting on pile head has different impact on the horizontal bearing capacity of the positive inclined piles and the negative inclined piles. The interaction between the batter pile and surrounding soil is mainly interactive compression, while the mutual shearing is relatively weak. There exists an effective length for horizontally loaded single batter pile and the effective length is notably affected by the module ratio of the pile and upper surrounding soil.2. The influence of cap embedded depth on the lateral response of low cap single batter pile was studied through 3-dimensional finite element analyses. The results show that the horizontal bearing capacity of the free-pile-top positive inclined pile is less than that of the low-cap positive inclined pile, and the horizontal bearing capacity increases with the deeper depth of pile cap, so do the negative inclined pile. The bending moment, shear force and axial force of the positive & negative batter pile are notably affected by the depth of pile cap.3. The influence of inclined angle on the horizontal bearing capacity and internal forces of the transmission tower batter pile group under different conditions was investigated. The results show that the horizontal bearing capacity of batter pile group is greater than that of vertical pile group. At the same condition, the bending moment, shear force of batter pile group decreases as the increasing of inclined angle. The effect of the shaft inclined angle on the axial force of batter pile group is significant.