Experimental observation and constitutive modelling of the shear strength of a natural unsaturated soil

Increasing frequency and intensity of extreme weather events in the Netherlands is raising attention on unsaturated response geo-infrastructures, promoting research projects to provide an overview impact conditions shallow soil layers embankments, better address maintenance mitigation measures. As part this effort, we discuss results standard laboratory tests performed initially samples retrieved from field tested natural conditions, as well after controlled drying wetting. The variation “undrained” (i.e. at constant water content) shear strength with degree saturation obtained aligns CPT measurements field. An elastic-plastic constitutive model mixed isotropic-rotational hardening developed for saturated soft soils was extended by following a robust approach previously compacted clayey soils. Coupling between mechanical hydraulic behaviour provided retention curve. nicely captures observed laboratory, until dry which possibly alter structure soil, peak stress, brittleness failure. capable reproducing effects previous history stress-strain over wide range saturation.