Consideration of batter angle in pseudo-static analyses of pile foundations

Inclined piles have been widely used in geotechnical practices due to the enhanced lateral stiffness of the foundations as a consequence of the lateral load transfer along the axial direction. However, the simplified analysis approach for this type of foundation is still not well-developed. Based on the conventional simplified seismic assessment of pile foundations, this paper proposes the pseudo-static analysis of inclined piles. Firstly, a series of three-dimensional (3D) numerical analyses was conducted using the OpenSees finite-element platform. The axial and shear capacities of single inclined piles embedded in a uniform soil continuum were investigated and compared with the capacities of vertical piles. Based on the results of the 3D numerical analyses, explicit relationships have been proposed to estimate the capacity ratios of inclined and vertical piles from the pile inclination, relative density of the soil, and the ratio of the stiffnesses of the pile and the soil. The properties of the soil springs, which were initially proposed for vertical piles, were then modified and adapted to the inclined condition. Finally, the modified springs were implemented in the pseudo-static method to evaluate the pile responses of four case studies from which a desirable agreement with the observations was achieved.