Accuracy of the Theory of Equivalent Thickness in Two-Layer System Applications with Geocell-Reinforced Soils

Geocells are geosynthetics mainly applied to shallows foundations and pavement reinforcements in geotechnical engineering. Its structure confines the infill soil, usually granular, generating a layer with improved behavior in terms of resistance (ultimate state) and displacements (service state). A possible methodology to model this geocell-reinforced layer is considering it as a composite with equivalent geomechanics parameters over the foundation or subgrade – which is usually a soil with reduced resistance/stiffness. This kind of situation configures a two-layer system, mathematically treated in a rigorous form by the theory of elasticity (TE) and by the theory of equivalent thickness (TET), an approximated method. This article makes a comparison among these theories and a multilayer analysis software evaluates the applicability and accuracy of these methods, especially considering the usual variations in the problem as regards geometry and elastic parameters. The analysis shows that the approximated solutions by TET yield compatible results as compared with the rigorous formulation and with the software, proving the viability of its application mainly for being simple and easy to employ and propose and adjust of the approximated method in its coefficients to enhance the fit with the TE.