D'ONZA F.

This paper presents a new method for selecting parameter values in elasto-plastic models for unsaturated soils under isotropic stress states. The proposed method is an improvement over more traditional calibration approaches as it explicitly takes into account experimental yielding behavior when defining the unsaturated normal compression...

The popularity of the Barcelona basic model (BBM) has grown steadily since its publication in 1990, due to its ability to capture key aspects of unsaturated soil behaviour. Nevertheless, the BBM is still rarely employed by practitioners, partly because of the absence of simple and objective methods for selecting parameter values from laboratory...

An analysis of results from published laboratory tests on Jossigny silt and Barcelona clayey silt is presented to confirm the existence of a unique capillary bonding function linking the quotient between unsaturated and saturated void ratio, at the same mean average skeleton stress, to a single capillary bonding scalar variable. The analysis...

The paper presents a soil water retention model that takes into account the effects of void ratio and hydraulic hysteresis on the variation of degree of saturation. Based on a modified form of the van Genuchten equation, the model defines two bounding surfaces, namely a main drying surface and a main wetting surface, which delimit the region of...

The paper presents a collaborative piece of research undertaken by seven research teams from different universities within the 'Mechanics of Unsaturated Soils for Engineering' (MUSE) network. The objective is to benchmark different approaches to constitutive modelling of mechanical and water retention behaviour of unsaturated soils by comparing...

Seven teams took part in a benchmarking exercise on selection of parameter values for the Barcelona Basic Model (BBM) from experimental data on an unsaturated soil. All teams were provided with experimental results from 9 tests performed on a compacted soil in order to determine values for the ten BBM soil constants and an initial value for the...