A Theoretical Model for the Pull-Out Response of Geosynthetic Reinforcement

Abstract

Soil-reinforcement pull-out tests are essential for evaluating the strength, integrity, and effectiveness of the soil-reinforcement system. In this paper, a new pull-out test model that calculates the soil-geosynthetic reinforcement interface shear stress for highly extensible geosynthetic reinforcement is proposed. Based on a new bilinear interface shear model, the geosynthetic pull-out test results are calculated with regard to the variation of the mobilised geosynthetic tension with distance, geosynthetic pre-yield and post-yield behaviour, and the effective and extended length of the geosynthetic reinforcement. The resulting nonlinear equation for the soil-geosynthetic interface shear stress pull-out mechanism is nondimensionalised, expressed in a finite difference form, and solved numerically using the Gauss-Siedel technique. A parametric study is carried out for a range of relative stiffness values and interface shear stresses. The normalised load-displacement relationship and the variation of the pull-out force and reinforcement displacements, with distance along the reinforcement, are presented. The values calculated using the proposed model are compared with experimental pull-out test results for a needle-punched, nonwoven geotextile, polyester fibres coated with polyethylene, and nylon reinforcements.

Soil-Geosynthetic Interface Strength and Stiffness Relationships From Pullout Tests

“…Values of G i were estimated using a technique described by Madhav et al (1998). Values of G i were estimated using a technique described by Madhav et al (1998).…”

“…Values of G i were estimated using a technique described by Madhav et al (1998). Madhav et al (1998) developed a nondimensional interface stiffness parameter, α, given by: By assuming small geosynthetic strain values, the solution was solved at the point of load application (x = 0).…”

“…For values of α greater than approximately 2.5, Madhav et al (1998) showed that α could also be calculated using:…”

“…A linear relationship was also assumed between shear stress and shear displacement for the interface for purposes of developing the governing differential equation. Madhav et al (1998) adopted a linear relationship for the geosynthetic, a bilinear elastic-perfectly plastic interface relationship, and no soil movement. Abra- GEOSYNTHETICS INTERNATIONAL S 1999, VOL.…”

Continuum Modeling and Analysis of Polymeric Sheet Reinforcement Subjected to Axial Pull

“…Madhav et al [30] presented a mechanical model to demonstrate the pullout response of geosynthetic reinforcement. Applied pullout force mobilizes soil reinforcement interface shear stress along the reinforcement quantified by the bilinear shear stress displacement response.…”