Numerical investigation of advancement ratio and helix plate number on stress response and soil disturbance during helical pile installation in sand

Abstract

The installation process of helical piles induces substantial changes in the surrounding soil, including stress redistribution, void ratio variation, and strain localization, all of which significantly influence pile performance. This study investigates the impact of advancement ratio (AR) and helix plate number on stress responses and soil disturbance during pile installation in dense sand. A density- and stress-dependent hypoplastic constitutive model is implemented within a Coupled Eulerian-Lagrangian (CEL) framework to capture the nonlinear and non-axisymmetric soil behavior. Parametric simulations involving single, double, and triple plate piles with varying AR values reveal that AR strongly governs the extent of stress concentration, dilation-induced loosening, and effective energy transfer into deep soil layers. Higher AR values intensify vertical compression, while multiple helix plates promote uniform compaction and reduce stress anisotropy. These asymmetric stress patterns shift stress centroids and generate directional stress concentration zones, which are critical for understanding helical pile-soil interaction.