Comparative Model Study of Geosynthetic Pull-Out Response

Abstract

This technical note describes the analysis of reinforcement pull-out tests using a shear model that incorporates a hyperbolic shear stress-displacement relation for the soil-reinforcement interface. Numerical studies of pull-out tests were performed for small to large strains in inextensible and extensible reinforcements. Predictions based upon a hyperbolic model of shear mobilisation are compared with a theoretical bilinear model presented by Madhav et al. in 1998. Comparative parametric studies using both models were carried out for ranges of relative stiffness and bond resistance values. Normalised load-displacement relations and the variations of pull-out force and displacements with distance, are presented for comparative evaluation. The finite difference equations of the hyperbolic model result in a faster convergence than the bilinear model. The incorporated hyperbolic model estimates the pre- and post-yield deformations, and shear stress and tensile force variations along the length of the reinforcement. Predictions of laboratory and field pull-out results from the available theoretical and experimental tests for inextensible steel straps, and extensible geotextiles, polymers, and nylon geosynthetics are also presented.