Experimental and Numerical Insights into the Uplift Behavior of Photovoltaic Helical Piles in Sand under Inclined Loading

Abstract This study examines the mechanical performance of photovoltaic (PV) helical pile foundations under inclined loading through prototype-scale laboratory tests and numerical simulations. The coupled Eulerian–Lagrangian method was employed to simulate the rotational installation of the piles. The influence of key parameters, including the number of helices, load inclination angle, embedment depth-to-diameter ratio ( H / D ), advance ratio (AR), and spacing ratio ( S / D ), on the bearing capacity, displacement response, and installation torque was systematically analyzed. The results show that soil disturbance generated during installation markedly decreases the lateral bearing capacity of helical piles. The AR is also identified as a key factor governing installation torque and shaping the resulting soil disturbance pattern. Overall, this work offers important insights into installation effects and pile behavior under inclined loading, providing practical guidance for optimizing PV pile foundation design.