Numerical simulation of pullout response for planar soil reinforcements
This paper presents a series of numerical simulations for laboratory and field pullout tests. A nonlinear differential expression for interface pullout from simple equilibrium of forces and hyperbolic interface model for shear displacement variation along the length of the planar reinforcement is utilised. Finite difference numerical method and nondimensional expressions are adopted for wider application. The relative stiffness and relative displacement parameters are defined and related to the interface pullout interaction mechanism. A parametric study to develop computer-simulated interface design charts for a practical range of relative stiffness and relative bond resistance is theoretically illustrated. The pullout model is capable of simulating the responses of inextensible as well as highly extensible planar reinforcements. The model responses compared satisfactorily with the available theoretical and experimental pullout test results for steel straps, polymer strips, geotextiles, geomembranes, nylon geosynthetics, and geogrid reinforcements.Key words: geosynthetics, extensible reinforcement, numerical simulation, parametric study, pullout testing, reinforced soil.