é Acquis et perspectives pour la mécanique des sols Prof. Lyesse Laloui Directeur
Laboratory Snapshot - Personnel Professors Senior Staff Post-Docs Lyesse Laloui Alessio Ferrari Fabrice Dupray Director Laurent Tacher Azad Koliji Laurent Vuillet Gilbert Gruaz Mohammad Monfared PHD students Key Employees Julien Rosa Ana Barbara Patrick Laurent Alice Ali Suzanne Marta John Wahid Nocera Turielle Tinguely Dubey Morier Di Donna Seiphoori Fauriel Rizzi Eichenberger Clémence Jessica Qazim Jérôme Bastien Albin Thomas Paul Donatella Chao Birbaum Garcia Llabjani Guex Pasquier Kazangba Mimouni Witteveen Manca Li
Some of the Recent LMS Alumni Doctors Doctors Geotechnical engineers & Technicians Dr. Rafal Obrzud Thibaud Meynet Prof. Bertrand François GeoMod & BG, Switzerland Karakas & Français SA, Switzerland Université de Liège, Belgium Dr. Emilie Rascol Christoph Knellwolf Prof. Mathieu Nuth Bureau Tissières SA, Switzerland CSD, Switzerland Université de Sherbrooke, Canada Dr. Azad Koliji Dr. Frédéric Mayoraz Matteo Moreni École Polytechnique Fédérale de Lausanne De Cérenville Géotechnique, Switzerland Pöyry INFRA , Switzerland STUCKY LTD, Switzerland Dr. Hervé Péron Dr. Georg Klubertanz Laurent Gastaldo CSD, Switzerland Emch+Berger AG, Switzerland EPFL, Switzerland Dr. Cane Cekerevac Dr. Françoise Geiser Jérôme Guex STUCKY LTD, Switzerland GeoMod & De Cérenville , Switzerland De Cérenville Géotechnique
Laboratory Snapshot - Focus NATURAL HAZARDS CIVIL ENGINEERING & CLIMATE CHANGES • Geotechnical and foundation engineering • Debris flows, landslides and • Soil -groundwater flows interaction their triggering mechanisms • In-situ and laboratory testing • Multidisciplinary analysis of • Soil-structure interactions risks related to soil slopes • Soil dynamics GEOENVIRONMENTAL ENERGY ENGINEERING • Energetic geostructures and thermal piles • Geological disposal of • Deep geothermal energy nuclear waste • Enhanced oil production • Effects of gas emissions • Field subsidence Our experimental and modeling resources are mobilized to understand, describe and predict the behaviour of natural and man-made systems.
Present Research Themes Constitutive and numerical modelling A dvanced C onstitutive M odels for E nvironmental G eomechanics: a general framework for THM modelling
Present Research Themes Experiment-based multi-physical modelling of Soils Development of an Advanced Experimental Soil Mechanics Laboratory, with several research-class prototype equipment to its credit. The laboratory is recognized Internationally as one of the Leading Centers for experimental research in Soil Mechanics.
Examples of present research themes • Natural Hazards and Climate Change • Nuclear Waste Storage • Heat Exchanger Geostructures
Natural Hazards and Climate Change Main ongoing projects Living with landslide risk in Europe ..Assessment Mountain Risks: from ..Risk management prediction to management ..Effects of global change and governance 25 institutions from 20 international 13 European countries institutions TRAMM COGEAR Triggering of Rapid Coupled seismogenic Mass Movements GEohazards in in Steep Terrain Alpine Regions • EU-WANDLAND (effects of wet-dry cycles on landslide activity): Marie Curie Reintegration Grant
Natural Hazards and Climate Change Predictive tools for a better assessment Empirical- Deterministic Statistical approach approach physical key mechanisms are uncertainty can well captured be taken into account future scenarios can be analyzed Risk associated with landslides is in general growing due to an increase in exposure and climate change
Natural Hazards and Climate Change Deep seated landslides In-situ measurements STEINERNASE LANDSLIDE -0.04 Numerical prediction (m) B Displacement (mm) -0.02 0 0 120 240 360 480 600 720 days Time (days) Comparison of model results and measurements Unit [m] Hydro-mechanical modelling of a natural slope affected by a multiple slip surface failure mechanism. [Ferrari, Laloui, and Bonnard 2009] Computed horizontal displacements (for the period 2000 – 2001) highlighting the concenration of displacements in the central part of the slope
Natural Hazards and Climate Change Shallow landslides in unsaturated soils t 2 t 0 t 1 t 3 t 4 t 5 Triggering of shallow landslides [Eichenberger, Nuth and Laloui 2010] S r = 0.32 q [mm/h] S r = 1 20 m 17 m 56m Active mechanism TRAMM in-situ experiment Inactive mechanism [Springman et al. 2009] 86m Hydraulic response Mechanical response Degree of saturation during rainfall event Development of plastic strains
Natural Hazards and Climate Change Landslide behaviour under seismic inputs • Governing Equations for Poro-elastoplastic Media σ div ' grad p g u u s f rf u K grad p ( g u u / ) n s rf f rf p div u div K grad p ( g u u / ) n t s s f rf Q • Cyclic Constitutive Model with Kinematic Hardening • Paraxial Elements simulated at the Interface
Natural Hazards and Climate Change Landslide behaviour under seismic inputs Earthquake triggered landslides [Li, Dupray, Seiphoori and Laloui 2011] 2cm 6cm Recent progress in modelling seismic propagation allows the use of a site-specific ground motion, combined with the use of advanced HM cyclic constitutive model. Ground motion input
Nuclear Waste Storage Nuclear waste storage and multi-barrier systems Third barrier: Argilaceous materials low permeability constitute one of the host rock key elements of the multi-barrier system First barrier: metal Second barrier: swelling clay
Nuclear Waste Storage Main ongoing projects Fate of repository gases. Thermal impact on the Understanding of how damaged zone of around a corrosion gases or vapour radioactive waste disposal in move in the repository. day host rocks 24 international 20 international institutions institutions ABM FEBEX Alternative Buffer Material Full-scale Engineered Long-term behaviour of several Barriers Experiment. types of buffer materials. Modeling of the in-situ test
Nuclear Waste Storage Experimental facilities (NSF R,Equip)
Nuclear Waste Storage [Ferrari, Seiphoori and Laloui 2011] Experimental facilities Inner cell system for Double PV controller for specimen volume • outer cell pressure control change assessment • Inner cell pressure control • inner cell volume change At each base : measurement • Air flushing • Water flushing 2 PV controllers for the • Pore air pressure control independent control of • Pore water pressure control the pwp at the two bases • water volume change measurement EPFL Advanced Triaxial System
Nuclear Waste Storage THM modelling of the FEBEX experiment Numerical simulations [Dupray, François and Laloui 2011] Hydraulic gradient Important thermal gradient/load • Granite -bentonite interface : resaturation of bentonite TCanister =100° ; Tfar-field = 12°C • Canister-bentonite interface: drying of bentonite
Heat Exchanger Geostructures Use of foundations and underground infrastructures for heat production and energy storage Today : Current technology uses 0-20°C range (GSHP+Free cooling). Future : But the 30-60°C (Solar heat+direct heating) can be foreseen in buildings T°>60°C will require development for storage -> Geotechnical challenges <- applications.
Heat Exchanger Geostructures Main ongoing projects Constructive recommendations for optimized and reliable heat GRETEL exchanger pile systems Geotechnical REliability of Thermo-piles Energy Sponsored by Swiss Federal storage in soils Office of Energy Heat storage system Heat exchanger for road anchors for thermo infrastructure active tunnels Study of energy geostructure Sponsored by Swiss Federal Roads for thermal regulation of road Office and Swiss Tunnelling Society infrastructure
Heat Exchanger Geostructures A software for geotechnical design of energy piles [Knellwolf, Péron and Laloui 2011] INNOVATIVE TRUSTWORTHY EASY & QUICK i le
Heat Exchanger Geostructures Thermal cyclic effect on energy piles [Di Donna, Dupray and Laloui] Geostructures modelling The effect of temperature changes on global foundation behaviour can be studied, helping engineers to design each pile, but also a globally efficient energy foundation. -3 0 x 10 0 Volumetric Plastic Strain [-] Volumetric Plastic Strain [-] -1 -0.002 -2 -0.004 2m depth -3 18m depth -0.006 2m depth 26m depth -4 18m depth 34m depth 26m depth 46m depth -0.008 34m depth 60m depth -5 Group of piles 46m depth 2D model 60m depth -0.01 -6 0 200 400 600 Seasonal thermal loading of 0 20 40 60 Time [months] group piles Time [months]
Heat Exchanger Geostructures Behaviour of a group of energy piles EnerFound – Behaviour of group piles [Mimouni, Dupray and Laloui] • Group effect on stress state of a group of piles • Cap rigidity effect on a group of piles • Temperature influence on piles bearing capacities • Sustainability of heat storage Top view of the four piles Swiss Tech Convention Center View of the hydraulic circuit tightened on the reinforcing rods.
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