Publications related to Mechanical testing in unsaturated soils

Pore-pressure coefficients for unsaturated soils: generalized effective stress approach

Lyesse Laloui, Alessio Ferrari, Angelica Tuttolomondo

Geotechnical problems with total stress changes occurring rapidly relative to the soil consolidation time can be conveniently addressed using an effective stress-based approach. For saturated states, analytical formulations of pore-pressure coefficients ad ...

CANADIAN SCIENCE PUBLISHING2023

Global Mapping of Potential and Climatic Plant‐Available Soil Water

Dani Or, Sara Bonetti

The estimation of plant-available soil water (PASW) is essential to quantify transpiration fluxes, the onset of heatwaves, irrigation water management, land-use decisions, vegetation ecology, and land surface memory in climate models. PASW is the amount of ...

2023

Role of Stress History on the Swelling-Shrinkage Behavior of Compacted Scaly Clay

Alessio Ferrari

Compacted scaly clays are complex geomaterials widely used for the realization of dam cores and waste dump liners. This research aims to investigate the swelling/shrinkage behavior of these geomaterials subjected in an oedometric cell to complex hydromecha ...

ASCE-AMER SOC CIVIL ENGINEERS2022

Life cycle environmental assessment of retaining walls in unsaturated soils

Alessio Ferrari, Gianluca Speranza

Retaining structures above groundwater level support soils that are usually in a state of partial saturation and subject to the actions of atmospheric agents. The current design approach considers the possible extremes of soil conditions - either totally d ...

ELSEVIER2022

Dynamic Effective Porosity Explains Laboratory Experiments on Watertable Fluctuations in Coastal Unconfined Aquifers

David Andrew Barry, Zhaoyang Luo

Watertable fluctuations are a characteristic feature of coastal unconfined aquifers. They interact with the vadose zone creating a dynamic effective porosity, for which a new (empirical) expression is proposed based on a dimensionless parameter related to ...

2023

Swelling and shrinkage of partially saturated gas shales: from laboratory tests to an effective stress framework

Jinwoo Kim

Gas shale swelling during hydraulic stimulation is one of the major challenges in unconventional gas development. It is hypothesized that the large volumetric strain upon water imbibition is a consequence of dramatic changes in capillary pressure and disjo ...

EPFL2022

Increasing temperature and vapor pressure deficit lead to hydraulic damages in the absence of soil drought

Pascal Turberg, Laura Mekarni, Charlotte Grossiord, Eugénie Isabelle Mas, Leonie Corine Schönbeck, Philipp Schuler

Temperature (T) and vapor pressure deficit (VPD) are important drivers of plant hydraulic conductivity, growth, mortality, and ecosystem productivity, independently of soil water availability. Our goal was to disentangle the effects of T and VPD on plant h ...

Wiley2022

Hydrothermal interactions in energy walls

Lyesse Laloui, Alessio Ferrari, Jacopo Zannin

Energy geostructures (EGs) employ heat exchangers embedded in concrete geostructures, such as piles, walls, tunnels, and sewers. In this study, energy walls (EWs) are studied with an emphasis on the following objectives: (1) to understand the fundamentals ...

2021

Geotechnical and environmental performance of retaining structures in unsaturated soils

Gianluca Speranza

Presently, environmental issues are considered as critical aspects concerning the market competitiveness in the building and construction sector. However, the construction sector is regarded as one of the main areas contributing to CO2 emissions and resour ...

EPFL2020

Watertable fluctuation-induced variability in the water retention curve: Sand column experiments

David Andrew Barry, Zhaoyang Luo

The soil water retention curve (WRC), describing the relation between the soil water content and its corresponding capillary pressure, relies not only on whether drying or wetting occurs but also on the pore scale water flow velocity. Here, we investigated ...

2020

Effects of large macropores on soil evaporation in salt marshes

David Andrew Barry

The occurrence of macropores in salt marsh sediments is a natural and ubiquitous phenomenon. Although they are widely assumed to affect pore-water flow in salt marshes significantly, the mechanisms involved and their extent are not well understood. We cond ...

2020

A generalised water retention model with soil fabric evolution

Lyesse Laloui, Yafei Qiao, Angelica Tuttolomondo, Xingbang Lu

This paper introduces a novel soil water retention curve model that considers two different mechanisms of water retention –namely capillarity and adsorption – and their evolution with soil fabric along a generalized stress path. The model is formulated bas ...

2021

An experimental investigation on the water retention behaviour of a silty soil for the computation of the lateral earth thrust on a retaining wall

Lyesse Laloui, Alessio Ferrari, Gianluca Speranza

Retaining structures often interact with soils in unsaturated conditions and their performance is influenced by environmental actions. Currently, geotechnical analysis and design approaches mainly consider the soils either totally dry or totally saturated. ...

E3S Web of Conferences2019

Velocities, Residence Times, Tracer Breakthroughs in a Vegetated Lysimeter: A Multitracer Experiment

Michaël Bensimon, Pierre Claude Jean Queloz, Andrea Rinaldo, Paolo Benettin

Flow velocities, residence times, and tracer breakthroughs at the lysimeter scale are affected by matrix properties and preferential flow. Despite their relevance to transport processes, however, the relative timing of preferential flow, and its link to tr ...

2019

Soil Moisture Estimation by SAR in Alpine Fields Using Gaussian Process Regressor Trained by Model Simulations

Jean-Philippe Thiran, Jelena Stamenkovic

In this paper, we address the problem of retrieving soil moisture over a grassland alpine area from Synthetic Aperture Radar (SAR) data using a statistical algorithm trained by simulations of a physical model. A time series of C-band VV-polarized Wide Swat ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Simulating the influence of snow surface processes on soil moisture dynamics and streamflow generation in an alpine catchment

Michael Lehning, Nander Wever, Francesco Comola, Mathias Thierry Pierre Bavay

The assessment of flood risks in alpine, snow-covered catchments requires an understanding of the linkage between the snow cover, soil and discharge in the stream network. Here, we apply the comprehensive, distributed model Alpine3D to investigate the role ...

Copernicus GmbH2017

Pore-scale analysis of the minimum liquid film thickness around elongated bubbles in confined gas-liquid flows

John Richard Thome, Alessio Ferrari, Mirco Magnini, Albert Matthias Beisel

The fluid mechanics of elongated bubbles in confined gas-liquid flows in micro-geometries is important in pore-scale flow processes for enhanced oil recovery and mobilization of colloids in unsaturated soil. The efficiency of such processes is traditionall ...

Elsevier Sci Ltd2017

Multiphysical behaviour of shales from Northern Switzerland

Valentina Favero

Shales are involved in energy-related applications such as the extraction of shale gas, the CO2 storage and the nuclear waste disposal. In these contexts, fundamental issues come along with the multiphysical conditions in which shales are found, where mech ...

EPFL2017

Modelling landslides in unsaturated slopes subjected to rainfall infiltration using material point method

Lyesse Laloui, Alessio Ferrari, Samila Sanjeevanie Bandara

This paper presents a dynamic fully coupled formulation for saturated and unsaturated soils that undergo large deformations based on material point method. Governing equations are applied to porous material while considering it as a continuum in which the ...

Wiley-Blackwell2016

Water retention behaviour of compacted bentonites: experimental observations and constitutive model

Anne-Catherine Adolphine M Dieudonné

Bentonite-based materials are studied as potential barriers for the geological disposal of radioactive waste. In this context, the hydro-mechanical behaviour of the engineered barrier is first characterized by free swelling conditions followed by constant ...

EDP Sciences2016