Yield design-based analysis of reinforced soil structures, making use of different models of reinforced soils

Abstract

This contribution is aimed at applying the static and kinematic methods of the yield design theory, initially developed for homogeneous soils, to the stability analysis of reinforced soil structures. Several mechanical models of reinforced soils are considered to this end, starting from the mixed modelling approach which is the most intuitive one, according to which the reinforcements are treated as one-dimensional beam elements embedded in the soil regarded as a three-dimensional continuum. While this first model is posing some difficulties as regards the implementation of the lower bound static approach, a homogenization procedure should be preferred in the case of a dense array of regularly spaced inclusions, leading to the formulation of a macroscopic strength condition for the homogenized reinforced soil. Since the latter formulation, unlike the mixed modelling approach, fails to account for the shear and flexural strength characteristics of the reinforcements, a continuum multiphase description of reinforced soils, which may be considered as an extension of the previous homogenization method, has been developed. Such a multiphase model, which combines the advantages of the two previous models, is able to incorporate in an explicit way not only the shear and bending strength capacities of the reinforcements, but also a specific failure condition at the soil-inclusion interface. This contribution presents some illustrative applications of the yield design theory and related upper and lower bound methods to the design of typical reinforced soil structures, using the three above mentioned models.