Numerical Study of Geogrid-Reinforced Retaining Wall

Geotechnical Engineering Journal of the SEAGS & AGSSEA ISSN 0046-5828

Vol. 54 No. 2 June 2023

Numerical Study of Geogrid-Reinforced Retaining Wall

Marwa Feligha, Fatima Zohra Benamara , Nouaouria Mohamed Salah, Benayoun Fadila, and Souhila Rehab Bekkouche

ABSTRACT: The use of geogrid-reinforced soil retaining walls has increased considerably, due to several advantages such as their relative and rapid construction, aesthetics and good seismic performance. The behavior of these structures is complex, which requires research to better understand the effect of certain parameters on the behavior of geogrid reinforced soil structures. The aim of this work is the numerical modeling of geogrid reinforced soil retaining wall with a segmental facing geogrid-reinforced retaining wall using the finite element code (PLAXIS2D). The objective of this work is to investigate the influence of some geometrical and mechanical parameters, on the behaviour of a geogrid-reinforced soil retaining wall to analyze numerically the peak tensile strength, lateral facing displacements, critical failure surfaces and safety factor. The numerical results show that the failure plane occurred in the reinforced zone at the mid-height, this observation contradicted the triangular distribution with depth assumed in conception methodologies for reinforced soil retaining wall. The distribution of peak tensile strength with depth was bilinear at high loading increments and became trapezoidal at low loading ones.

Furthermore, it was found that the behaviour of a geogrid-reinforced soil retaining wall is independent of loading increments width beyond 0.5H, which coincides with the Ranking failure surface. It also seems that the location of the loading increments and the loading values can change the shape and the position of the peak tensile strength mobilized along the geogrid from a position closer to the facing to the soil reinforcement, which is more pronounced for the higher loading values. As far as the present study is in agreement with the AASHTO conception method according to which the failure surface, was based on the Rankine plane for a vertical facing and the Coulomb plane with an inclined facing ω ≥ 10°. It also seems that the geogrid inclination angle has a major effect on the lateral facing displacements and safety factor, these results have major implications for conception. The soil-geogrid friction ratio is not considered to have a major effect on the peak tensile strength value for friction ratio greater than 4/7φ.

KEYWORDS: Failure surface, PLAXIS2D, Retaining walls, Reinforced soil, and Tensile strength.

DOI: 10.14456/seagj.2023.20