Multiphase approach as a generalized homogenization procedure for modelling the macroscopic behaviour of soils reinforced by linear inclusions

This paper examines the possibility of applying a homogenization procedure to soils reinforced by linear inclusions, regarded as elastic periodic composites for which scale effects have to be considered, as shown by the preliminary numerical analysis of two illustrative problems. A so-called multiphase model is developed for this purpose, aimed at improving the classical homogenization method on two decisive points. First, by modelling the reinforced soil at the macroscopic scale as the superposition of two mutually interacting continuous phases, describing the soil and the reinforcement network, respectively. Second, by assuming that the reinforcements display a shear and flexural behaviour, in addition to the axial one, so that the corresponding phase may be described as a micropolar continuum. Its is shown that such a multiphase approach can be interpreted as an extension of the homogenization procedure, making it thus possible to capture the previously mentioned scale effects, provided that the constitutive parameters of the model can be properly identified from the reinforced soil characteristics.