Physical models at increasing scale and role of theoretical / numerical back-analyses

In spite of advancements in the techniques for the study of thermo-hydro-chemomechanical behaviour of geomaterials at the REV scale, the latter might not provide an exhaustive picture of transport processes in soil, when non-linear coupling terms arise, and when scale effects are expected. To overcome the difficulties associated with this issue, physical models, in which relevant coupled fields may be tracked in time, can be developed. Most often, theoretical and / or numerical models must accompany the interpretation of the physical test, to exploit all the information provided by measurements. In this chapter a few examples of increasing complexity are briefly presented to discuss this viewpoint and to show the potentialities provided by physical models aided by theoretical and numerical interpretation in the comprehension of coupled behaviour.