Analytical model for laterally loaded pile groups in layered sloping soil

The historic canal wall structures in many Northern European cities have been built as masonry walls on a timber deck founded on timber piles. For analysis of the resistance of those structures and assessment of their remaining service life, suitable and accurate calculation models needed. Thereto an analytical method was developed for modelling laterally loaded pile groups layered sloping soil. In the proposed method, the bending of a pile, which is subjected to a lateral load and axial load, is described by a beam on a Winkler elastic foundation in which the behaviour is represented by a series of independent p-y springs, idealized with a bilinear elastic perfect-plastic approximation. The plastic limit was computed with Brinch Hansen ultimate resistance and the elastic soil response by the Me & PRIME;nard stiffness. The plastic limit was corrected each depth, based on the reduction of the passive soil wedge due to pile group effects and presence of a sloping surface. The analytical model was calibrated and validated with three experiments, one full-scale lateral load test of a 3 x 5 pile group in soft clays and silts (Snyder, 2004), one full scale lateral load test of a single pile located on a slope in layered soils (Mirzoyan, 2007) and one small scale lateral load test of a single pile located near a slope in sand (Abdelhalim et al., 2020). The proposed method can adequately predict bending moment distributions and deflections and in addition, a good consistency between the analytical model and experimental tests was observed. The method is very fast, making it suitable for probabilistic, Monte Carlo simulations and reliability updating to determine the probability of failure of quay walls or structures with horizontally loaded piles.

Automated summary

The historic canal wall structures in many Northern European cities have been built using masonry walls on timber decks founded on timber piles. A proposed analytical method has been developed to model laterally loaded pile groups in layered sloping soil. The method accurately predicts bending moment distributions and deflections, and has been validated with experimental tests. Its speed makes it suitable for probabilistic simulations and determining the failure probability of quay walls or structures with horizontally loaded piles.