Modelling of imbibition process in an embankment scale model

Giada M Rotisciani,Giulio Sciarra,Francesca Casini,Augusto Desideri

doi:10.1051/e3sconf/20160916009

Giada M Rotisciani, Giulio Sciarra + Show 2 more

Open Access

https://doi.org/10.1051/e3sconf/20160916009

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Abstract

This paper aims to investigate the hydro-mechanical behaviour of a loosely compacted embankment during an inundation event. This study is based on the results of a centrifuge test carried out on a small-scale embankment model made of an artificially compacted clay-sand mixture. The wetting-induced displacements are analyzed and interpreted by means of a constitutive model adapted to unsaturated conditions. The numerical predictions are presented in terms of time evolutions of settlements, as well as, spatial distributions of vertical displacements. These profiles are compared to those experimentally observed in order to validate the predictive capabilities of the model on a boundary value problem. Moreover, the stress paths followed by elementary soil elements located at different depths are analyzed to emphasize the stress and strain variations due to capillary rise.

Highlights

Soils used in the construction of roadway and railway embankments are usually in partial saturation regime
The hydro-mechanical behaviour of the solid skeleton is described using the Modified Cam-Clay model extended to unsaturated conditions ([2])
The ability of this model to reproduce the response of elementary soil volumes has been verified over the years by several authors ([3], [4], [5])

Summary

Introduction

Soils used in the construction of roadway and railway embankments are usually in partial saturation regime Once wetted, these materials can collapse causing extensive crest settlements. The hydro-mechanical behaviour of the solid skeleton is described using the Modified Cam-Clay model extended to unsaturated conditions ([2]). The ability of this model to reproduce the response of elementary soil volumes has been verified over the years by several authors ([3], [4], [5]). The numerical results presented here highlight the satisfactory capabilities of the Modified Cam Clay model in reproducing the effects induced by imbibition processes. The stress paths resulting from the imbibition process and the volumetric behaviour are analysed with reference to two different soil elements

Centrifuge test

Numerical modelling

Numerical model

Numerical results

Conclusion