Development and verification of a numerical model for the analysis of geosynthetic-reinforced soil segmental walls under working stress conditions

Abstract

The paper describes a numerical model that was developed to simulate the response of three instrumented, full-scale, geosynthetic-reinforced soil walls under working stress conditions. The walls were constructed with a fascia column of solid modular concrete units and clean, uniform sand backfill on a rigid foundation. The soil reinforcement comprised different arrangements of a weak biaxial polypropylene geogrid reinforcement material. The properties of backfill material, the method of construction, the wall geometry, and the boundary conditions were otherwise nominally the same for each structure. The performance of the test walls up to the end of construction was simulated with the finite-difference-based Fast Lagrangian Analysis of Continua (FLAC) program. The paper describes FLAC program implementation, material properties, constitutive models for component materials, and predicted results for the model walls. The results predicted with the use of nonlinear elastic-plastic models for the backfill soil and reinforcement layers are shown to be in good agreement with measured toe boundary forces, vertical foundation pressures, facing displacements, connection loads, and reinforcement strains. Numerical results using a linear elastic-plastic model for the soil also gave good agreement with measured wall displacements and boundary toe forces but gave a poorer prediction of the distribution of strain in the reinforcement layers.Résumé : Cet article décrit un modèle numérique qui a été développé pour simuler la réponse de trois murs de sol à pleine échelle, instrumentés, armés de géosynthétique et soumis à des conditions de contraintes de travail. Les murs ont été construits avec un parement de colonnes d'unités modulaires solides en béton et un remblai de sable propre uniforme sur une fondation rigide. L'armature du sol comprenait différents arrangements de matériel d'armature en faible géogrid biaxial de polypropylène. Les propriétés du matériau de remblai, la méthode de construction, la géométrie du mur et les conditions aux frontières étaient par ailleurs nominalement les mêmes pour chaque structure. On a simulé la performance des murs d'essais jusqu'à la fin de la construction au moyen du programme FLAC basé sur les différences finies. Cet article décrit l'implémentation du programme FLAC, les propriétés du matériau, les modèles constitutifs pour les matériaux impliqués et les résultats prédits pour les murs modèles. On montre que les résultats prédits au moyen des modèles non linéaires élastiques plastiques pour le sol de remblai et les couches d'armature sont en bonne concordance avec les forces mesurées à la pointe de la fondation, les pressions verticales sur la fondation, les déplacements du parement, les charges aux joints, et les déformations des armatures. Les résultats numériques obtenus au moyen d'un modèle linéaire élasto-plastique pour le sol a aussi donné une bonne concordance avec les déplacements mesurés du mur et les forces à la pointe, mais ont donné une mauvaise prédiction de la distribution ...

A Simple Analysis of Reinforced Soil Using Equivalent Approach

“…Ling and Leshchinsky [5], Hatami and Bathurst [7,8] and Guler et al [9] verified their numerical models against carefully constructed, instrumented and monitored walls. Reviews of numerical modelling of geosynthetic reinforced soil wall can be found in the papers by Bathurst and Hatami [10] and Ling [11].…”

“…8 Comparison of stress-strain curves of WGT reinforced sand (RD-40 %, r 3 -50 kPa) based on equivalent and discrete approach Fig. 9 Comparisons of stress-strain curves of WGT reinforced sand (RD-40 %, r 3 -50 kPa) using Mohr-Coulomb and Duncan-Chang model scale geogrid reinforced retaining wall constructed at Royal Military College of Canada (RMC) [7,8] and a reinforced retaining wall problem analysed by Guler et al [9] were analysed using FLAC. The equivalent numerical model is systematically verified with the instrumented data together with results from discrete approach.…”

“…Good amount of literature is available in modelling reinforced soils using numerical approaches like Karpurapu and Bathurst [1], Nakane et al [2], Rowe and Ho [3], Leshchinsky and Vulova [4], Ling and Leshchinsky [5] and Yoo and Song [6], Hatami and Bathurst [7,8], Guler et al [9] amongst many others. Ling and Leshchinsky [5], Hatami and Bathurst [7,8] and Guler et al [9] verified their numerical models against carefully constructed, instrumented and monitored walls.…”

Sensor-Enabled Geogrids for Stabilization and Performance Monitoring of Earth Structures: State of Development

“…Examples include stabilization of highway slopes and embankments [4], and reinforcement of foundations [5,6], and paved and unpaved roads [7][8][9] in order to mitigate cracking and rutting, prolong service life and reduce aggregate base course thickness for a given traffic volume.…”

“…Yazdani et al [27] modified a standard direct shear test apparatus and used it to investigate the influence of confining pressure on the tensoresistive response of PVC-coated PET yarn SEGG. They carried out their in-soil tensile tests at three different confining pressures of 10, 30 and 50 kPa to represent upper levels of reinforced soil structures where larger deformations typically occur [4]. It was found that greater confining pressures and strain rates both reduce the tensoresistivity of SEGG samples (Fig.…”