World Journal of Engineering | 2021
3D numerical analysis of pile response due to soil movements induced by an adjacent deep excavation
Abstract
\nPurpose\nThis paper aims to investigate single pile and pile group responses due to deep braced excavation-induced soil movement in soft clay overlying dense sand. The analysis focuses first on the response of vertical single pile in terms of induced bending moment, lateral deflection, induced axial force, skin resistance distribution and pile settlement. To better understand the single pile behaviour, a parametric study was carried out. To provide further insights about the response of pile group system, different pile group configurations were considered.\n\n\nDesign/methodology/approach\nUsing the explicit finite element code PLAXIS 3\u2009D, a full three-dimensional numerical analysis is carried out to investigate pile responses when performing an adjacent deep braced excavation. The numerical model was validated based on the results of a centrifuge test. The relevance of the 3\u2009D model is also judged by comparison with the 2\u2009D plane strain model using the PLAXIS 2\u2009D code.\n\n\nFindings\nThe results obtained allowed a thorough understanding of the pile response and the soil–pile–structure interactions phenomenon. The findings reveal that the deep excavation may cause appreciable bending moments, lateral deflections and axial forces in nearby piles. The parametric study showed that the pile responses are strongly influenced by the excavation depth, relative pile location, sand density, excavation support system and pile length. It also showed that the response of a pile within a group depends on its location in relation to the other piles of the pile group, its distance from the retaining wall and the number of piles in the group.\n\n\nOriginality/value\nUnlike previous studies which investigated the problem in homogeneous geological context (sand or clay), in this paper, the pile response was thoroughly studied in a multi-layered soil using 3\u2009D numerical simulation. To take into account the small-strain nonlinear behaviour of the soil, the Hardening soil model with small-strain stiffness was used in this analysis. For a preliminary design, this numerical study can serve as a practical basis for similar projects.\n