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In the present study, a strategy to assess liquefaction risk of road infrastructures has been proposed, as combination of liquefaction hazard, infrastructures vulnerability and exposure of transportation network. The proposed methodology includes a capacity analysis of the road network performed on both pre- and post-liquefaction scenarios to evaluate the social cost in terms of delay cost suffered by the transportation system. The approach has been applied to the municipality of Terre del Reno (Italy), that in 2012 suffered a severe seismic sequence that induced extensive liquefaction evidences over the territory. A multi-layer database, on a Geographical Information Systems (GIS) platform, has been created, with the aim to overlap information about subsoil, earthquake intensity, groundwater depth and road network configuration. The Vulnerability of road has been evaluated by the settlements of embankment on liquefied soils and, according to the damage level occurred, a loss of functionality has been assigned. Finally, performing a transportation analysis, the effects on the traffic conditions have been evaluated in terms of Total Delay Cost, suffer by the road users. Preliminary results showed a redistribution of the traffic flows caused by the service loss of crucial road sections due to the liquefaction evidences on the transportation network and the related Total Delay Cost has been quantified.

Strain localisation influences the behaviour of sheared soils in a way that the assumption of the continuum loses validity and may become inapplicable. This occurrence affects the interpretation of triaxial tests where samples are usually considered as representative elements of an equivalent continuum and a phenomenological interpretation is carried out to calibrate constitutive models. Considering the inherent and stress-induced heterogeneity of the material as a possible precursor of localisation, the evolution of porosity and strain fields is studied interpreting with statistical and geostatistical analyses, the results of X-ray computerised microtomography. The study is performed on sandy samples sheared in triaxial compression and extension. The analysis carried out before shearing shows a meaningful statistical heterogeneity of the porosity with correlation lengths to the order of a few grain diameters. The evolution on shearing reveals the onset of a second statistical population and of an anisotropic spatial variation dictated by strain localisation.

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