Interface pullout resistance of polymeric strips embedded in marginal tropical soils

• Published in: Geotextiles and geomembranes 2022-02, Vol.50 (1), p.20-39
• Main Authors: Pierozan, R.C., Araujo, G.L.S., Palmeira, E.M., Romanel, C., Zornberg, J.G.
• Format: Article
• Language: English
• Subjects: Coarse-grained soils; Coefficient of friction; Concrete pavements; Fly ash; Geosynthetics; Initial stresses; Interface shear resistance; Mathematical models; Polymeric strips; Pull out tests; Pull-out resistance; Pullout resistance; Reinforced soil; Shear strength; Soil fertility; Soil properties; Soil structure; Soils; Tropical soils
• ISSN: 0266-1144; 1879-3584
• DOI: 10.1016/j.geotexmem.2021.08.004

This paper presents an experimental and analytical evaluation of factors affecting the interface pullout resistance of polymeric strips embedded in marginal soils, with a particular interest in supporting the partial replacement of natural sands by intensely weathered tropical soils in reinforced soil structures, which have often been considered marginal fills in design guidelines. Large-scale pullout tests were conducted to evaluate the soil-geosynthetic interface pullout resistance, which also provided quantitative insight into the local increases in vertical stresses acting on the reinforcements due to pullout. Based on the experiments, analytical models were developed and calibrated to establish the relationship between confinement and soil-geosynthetic interface pullout resistance. The relationship between actual and initial stresses could then be represented in terms of a linear model in which the angular coefficient corresponds to the ratio between the apparent and actual friction coefficients (f*/f). This analytical relationship was found to represent a useful design tool since it directly correlates with soil geotechnical properties. The use of lateritic soils to partially replace coarse-grained soils in reinforced soil structures was found to be feasible for mixtures involving up to 25% of lateritic soils, with higher fractions affecting the interface resistance significantly. •The apparent friction coefficients (f*) may not be representative of the actual stress configuration.•Actual friction coefficients (f) are largely impacted by the local increases in vertical stresses induced by the pullout of the reinforcements.•The relation between actual and initial stresses was expressed in terms of a linear equation with an angular coefficient corresponding to f*/f.•The f*/f relation can be used to predict pullout responses based on the geomechanical properties of the fill.•A lateritic soil fraction below 25% can lead to enhanced pullout performance due to a more favorable stress distribution.