Analytical solutions for head-anchored piles for landslide stabilisation

This study presents analytical solutions for head-anchored stabilising piles embedded in a two-layer landslide. The landslide consists of a sliding soil layer with either a constant or linearly increasing profile of limiting pile–soil contacting pressure, and a stable, stiffer layer below with a uniform distribution of subgrade reaction modulus and ultimate reaction pressure throughout the depth. Rigid pile behaviour in the stable layer is assumed to simplify the analytical model. Based on the level of soil pressure mobilisation in the stable layer, three distinct pile modes are identified. For each mode, an analytical procedure is derived to calculate the lateral anchor force and various pile responses, including lateral head displacement, pile resistance, and maximum bending moment. Five scaled model tests from the literature are calculated for verification, and parametric studies are conducted to delineate the pile mode boundaries and investigate the impact of various parameters on the responses of the stabilising structure, providing valuable insights to guide preliminary design.