KYT 2018: Bentoniteinvestigations -...

07 April 2017

WojciechT. Sołowski

KYT 2018: Bentonite investigations

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Bentonite!

THEBES goals

Experimental research

Data for modelling

Creation & validation of

numerical models

Implementation into numerical software

Case studies

feedback loop feedback loop

Soft clay barriers:thermo – hydro – mechanical – chemical

coupling

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Outline

I. Introduction & overview II. Research at Aalto

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Bentonite

Highly compactedbricks, made of dry bentonite, used to construct a barrier preventing possible contamination

during construction

during dismantling

© Villar, 2016

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Bentonite

during construction

during dismantling

Dry compacted bentonite bricks swell if wetted, hopefully leading to a self-healing and impermeable barrier

© Villar, 2016

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Bentonite - microstructure

Bentonite behaviour is complex and to predict it reliably we need to understand the physical processes which leads to the observable macroscopic behaviour

© Villar, 2016

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Bentonite behaviour is complex and to predict it reliably we need to understand the physical processes which leads to the observable macroscopic behaviour

© Villar, 2016© Lloret et al. 2003


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Bentonite - microstructure Forces acting in bentonite:

Macroscale: forces from mechanical loading

Meso: capillary forces due to water menisci between aggregates

Micro: Forces within laminae of clay minerals (mainly montmorillonite) – inter-particle distance exceeds ~30-40 Å van der Waals attraction & electric repulsion on atomic levelinter-particle distance below ~10-20 Å –electric repulsion on atomic level

© Santamarina, 2001

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Bentonite swellling

1. Number of Montmorillonite platelets in a pile decrease, spacing between them increase.

Interlaminar porosity increases.

Some swelling occurs.

More water in the smallest pores

© Villar, 2016

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Bentonite swelling

2. Size of the aggregates changes. They become also more easy to break. Double porosity structure slowly disappears

Interlaminar porosity still increases.

More some swelling occurs.

© Delage et al. 2006

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Bentonite swelling: montmorillonite water absorption

3. Amount of water between layers of montmorillonite changes

Additionally, the swelling is affected by the mesoscale – size of the aggregates changes and capillary forces make a difference

© Delage, 2015© Sayiouri et al. 2000

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Bentonite swelling

4. Swelling pressure is affected by the mechanical, thermal, conditions, as well as availability of water and water composition (e.g. salinity).

Similarly, the number of layers / volume change is different for different mechanical conditions: complex thermo-hydro-mechanical-chemical coupling

© Delage, 2015

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Water transportDue to complex microstructure, water transport is complex, mixture of transport via vapour and liquid.

Also highly temperature dependent

Necessary to predict swelling, as swelling depends on amount of water available.

© Delage, 2015

Prediction in time is crucial, as material is affected by stress history

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TemperatureTemperature affects forces between particles, both in microscale, as well as mesoscale.

Therefore the material properties are temperature dependent.

Thermal conductivity non-linear and coupled to water & mechanical properties

© Tang et al., 2008Prediction in time is crucial, as material is affected by stress history

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Water salinity affects the hydraulic behaviour of bentonite, as well asmechanical properties. It also affects the swelling of bentonite aggregatesand generally lowers the swelling pressure.

Salinity effects

© Manca et al., 2016

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Water in liquid phase transport salt, but water vapour not!In non-isothermal condition creation of high saline zones (zonereached wetted by liquid water which evaporates) likely. Effects onmaterial being investigated.

Salinity effects

© Manca et al., 2016

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Outline

I. Introduction & overviewII. Research at Aalto

I. THMC modelling of bentonite / swelling clays

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Thermo-hydro-mechanical FE framework

mechanical: amended BBM, models by della Vecchia et al. (2013, 2014, 2015), new models which take into account micro and macro structure of bentonite are in development

hydraulic: number of models for water retention, Philip & De Vries model for vapourtransport, extended Darcy law for liquid water transport, Henry’s law for solubility of water, phase changes and heat effects are taken into account

thermal: heat flux in solid, water and gas phases, full energy balance / coupling

Taking into account well established laws of physics and thermodynamics

Some experiments on water retention behaviour of MX80 bentonite and its microstructure in saline solutions leading to inclusion of those into modelling (chemical coupling)

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Barcelona Basic Model (Alonso et al. 1990)

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mechanical: BBM (Alonso et al. 1990)

parameterκ

(-)

𝜿𝜿𝒔𝒔(-)

𝒌𝒌

(-)

𝑮𝑮

(MPa)

𝜷𝜷

(MPa-1)

𝒓𝒓

(-)

𝝀𝝀(𝟎𝟎)

(-)

𝒑𝒑𝒄𝒄

(kPa)

𝑴𝑴

(-)

𝑵𝑵(𝟎𝟎)

(-)

𝒑𝒑𝟎𝟎∗

(kPa)

value 0.02 0.117 0.08 10.1 0.05 0.20 0.5 41 0.5 6.36 variable

accuracy +0.005-0.01

+0.10

-0.01

+0.0

-0.05±0.5 +0.5

-0.02

+0.2

-0.0

+0.0

-0.2±30 +0.1

-0.05±0.5 −

Porté, Abed & Sołowski (in preparation)

parameters established based on:- Tang et al. (2008), PhD Thesis, Ecole des Ponts- Villar (2005), Ciemat technical report, CIEMAT/DIAE/54540/5/04- Seiphoori (2014), PhD thesis, Ecole Polytechnique Federale de Lausanne- Dueck and Nilsson (2010), SKB Technical report, TR-10-32- Dueck et al. (2010), SKB Technical report, TR-10-55

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mechanical: amended BBM – enhanced for temperature effects

Abed & Sołowski (2017)

Salinity effects on mechanical behaviour: in progress

𝑝𝑝𝑜𝑜𝑜𝑜∗ = 𝑝𝑝𝑜𝑜∗ + 2 𝛼𝛼1Δ𝑇𝑇 + 𝛼𝛼3Δ𝑇𝑇 Δ𝑇𝑇 , Gens (1995)

𝑝𝑝𝑜𝑜𝑜𝑜∗ = 𝑝𝑝𝑜𝑜∗ 1 − 𝛾𝛾𝑜𝑜 log𝑇𝑇 − 𝑇𝑇𝑟𝑟𝑟𝑟𝑟𝑟𝑇𝑇𝑜𝑜 − 𝑇𝑇𝑟𝑟𝑟𝑟𝑟𝑟

or

Laloui & Cekerevac (2003)

𝜀𝜀𝑟𝑟𝑜𝑜 =𝛼𝛼𝑜𝑜 + 𝛼𝛼2 𝑇𝑇 − 𝑇𝑇𝑜𝑜 ��𝑇

3𝜅𝜅 = 𝜅𝜅𝑜𝑜 1 + 𝛼𝛼𝜅𝜅𝑠𝑠

Changes in elasticity:

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hydraulic: number of models for water retention, Philip & De Vries model for vapour transport, extended Darcy law for liquid water transport, Henry’s law for solubility of air, phase changes and heat effects are taken into account. Also gas flow.

𝒒𝒒𝑙𝑙 = −𝐾𝐾𝑙𝑙 𝛻𝛻ℎ𝑤𝑤 + 1 Liquid phase

𝒒𝒒𝑔𝑔 = −𝐾𝐾𝑔𝑔 𝛻𝛻ℎ𝑔𝑔 +𝜌𝜌𝑔𝑔

𝜌𝜌𝑤𝑤𝑙𝑙gas phase

Advective liquid and gas flow (transport due to head difference):

𝐾𝐾𝑙𝑙 = 𝐾𝐾𝑠𝑠𝑠𝑠𝑠𝑠𝑙𝑙𝑆𝑆𝑙𝑙 − 𝑆𝑆𝑟𝑟𝑟𝑟𝑠𝑠𝑙𝑙

𝑆𝑆𝑠𝑠𝑠𝑠𝑠𝑠𝑙𝑙 − 𝑆𝑆𝑟𝑟𝑟𝑟𝑠𝑠𝑙𝑙

3

𝐾𝐾𝑠𝑠𝑠𝑠𝑠𝑠𝑙𝑙 =𝑔𝑔𝜌𝜌𝑤𝑤𝑙𝑙 𝑘𝑘𝑠𝑠𝑠𝑠𝑠𝑠𝑙𝑙

𝜇𝜇𝑙𝑙

𝑘𝑘𝑠𝑠𝑠𝑠𝑠𝑠𝑙𝑙 = 𝑘𝑘𝑟𝑟𝑟𝑟𝑟𝑟𝑙𝑙 𝑛𝑛3

1 − 𝑛𝑛 21 − 𝑛𝑛𝑟𝑟𝑟𝑟𝑟𝑟

2

𝑛𝑛𝑟𝑟𝑟𝑟𝑟𝑟3 𝜇𝜇𝑙𝑙 = 243.18 × 10−7 10247.8𝑜𝑜−140


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gas phase𝒒𝒒𝑔𝑔 = −𝐾𝐾𝑔𝑔 𝛻𝛻ℎ𝑔𝑔 +𝜌𝜌𝑔𝑔

𝜌𝜌𝑤𝑤𝑙𝑙

Advective liquid and gas flow:

𝐾𝐾𝑔𝑔 = 𝐾𝐾𝑑𝑑𝑟𝑟𝑑𝑑𝑔𝑔 𝑆𝑆𝑔𝑔 − 𝑆𝑆𝑟𝑟𝑟𝑟𝑠𝑠

𝑔𝑔

𝑆𝑆𝑑𝑑𝑟𝑟𝑑𝑑𝑔𝑔 − 𝑆𝑆𝑟𝑟𝑟𝑟𝑠𝑠

𝑔𝑔

3

𝐾𝐾𝑑𝑑𝑟𝑟𝑑𝑑𝑔𝑔 =

𝑔𝑔𝜌𝜌𝑤𝑤𝑙𝑙 𝑘𝑘𝑑𝑑𝑟𝑟𝑑𝑑𝑔𝑔

𝜇𝜇𝑔𝑔𝜇𝜇𝑔𝑔 = 1.48 × 10−6

𝑇𝑇

1 + 119𝑇𝑇


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Philip & De Vries : also non-advective flow of water vapour

𝒋𝒋𝒘𝒘𝒈𝒈 = 𝒋𝒋𝒗𝒗𝒘𝒘

𝒈𝒈 + 𝒋𝒋𝒗𝒗𝒗𝒗𝒈𝒈 = −𝐷𝐷𝑣𝑣𝑤𝑤𝛻𝛻ℎ𝑤𝑤 + 𝐷𝐷𝑣𝑣𝑤𝑤𝛻𝛻ℎ𝑔𝑔

𝑚𝑚𝑜𝑜𝑚𝑚𝑠𝑠𝑠𝑠𝑚𝑚𝑟𝑟𝑟𝑟 𝑠𝑠𝑟𝑟𝑟𝑟𝑚𝑚

− 𝐷𝐷𝑣𝑣𝑜𝑜𝛻𝛻𝑇𝑇𝑠𝑠𝑟𝑟𝑚𝑚𝑡𝑡𝑟𝑟𝑟𝑟𝑠𝑠𝑠𝑠𝑚𝑚𝑟𝑟𝑟𝑟 𝑠𝑠𝑟𝑟𝑟𝑟𝑚𝑚

𝐷𝐷𝑣𝑣𝑤𝑤 = 𝐷𝐷𝑠𝑠𝑠𝑠𝑚𝑚𝑣𝑣𝑣𝑣𝜙𝜙𝑔𝑔𝜏𝜏𝜌𝜌𝑤𝑤𝑔𝑔 𝑔𝑔𝑀𝑀𝑤𝑤𝑅𝑅𝑇𝑇

𝐷𝐷𝑣𝑣𝑜𝑜 = 𝑓𝑓𝑜𝑜𝑣𝑣𝐷𝐷𝑠𝑠𝑠𝑠𝑚𝑚𝑣𝑣𝑣𝑣𝜙𝜙𝑔𝑔𝜏𝜏𝜌𝜌𝑤𝑤𝑔𝑔 4974.0

𝑇𝑇2 +𝑔𝑔𝑀𝑀𝑤𝑤𝜓𝜓𝑅𝑅𝑇𝑇2

𝐷𝐷𝑠𝑠𝑠𝑠𝑚𝑚 = 2.2 × 10−5𝑃𝑃𝑠𝑠𝑠𝑠𝑚𝑚𝑃𝑃𝑔𝑔

𝑇𝑇𝑇𝑇𝑜𝑜

1.75


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Henry’s law

𝐻𝐻 =𝜌𝜌𝑤𝑤𝑙𝑙

𝐻𝐻𝑐𝑐𝑅𝑅𝑇𝑇𝑀𝑀𝑤𝑤

𝜕𝜕𝐻𝐻𝜕𝜕𝑡𝑡

= 𝑔𝑔𝜌𝜌𝑤𝑤𝑙𝑙 𝛽𝛽𝑤𝑤𝑡𝑡𝐻𝐻𝜕𝜕ℎ𝑤𝑤𝜕𝜕𝑡𝑡

+1𝑇𝑇− 𝛽𝛽𝑤𝑤𝑜𝑜 𝐻𝐻

𝜕𝜕𝑇𝑇𝜕𝜕𝑡𝑡

Coupling:Formulation include mass balance for the phases and changes in density due to all the factors. Coupling due to saline concentration is being developed.


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coupling: mass balance of solid, liquid and dry air

solid:

𝜕𝜕𝑛𝑛𝜕𝜕𝑡𝑡 = 1 − 𝑛𝑛

𝜕𝜕𝜀𝜀𝑣𝑣𝜕𝜕𝑡𝑡 + 𝛽𝛽𝑠𝑠𝑡𝑡

𝜕𝜕𝑝𝑝𝜕𝜕𝑡𝑡 − 𝛽𝛽𝑠𝑠𝑜𝑜


𝜕𝜕 𝜙𝜙𝑠𝑠𝜌𝜌𝑠𝑠

𝜕𝜕𝑡𝑡+ 𝛻𝛻 � 𝜙𝜙𝑠𝑠𝜌𝜌𝑠𝑠𝒗𝒗𝑠𝑠 = 0,

𝜌𝜌𝑠𝑠 = 𝜌𝜌𝑠𝑠𝑜𝑜𝑒𝑒𝛽𝛽𝑠𝑠𝑠𝑠 𝑡𝑡−𝑡𝑡𝑟𝑟𝑟𝑟𝑟𝑟𝑜𝑜 −𝛽𝛽𝑠𝑠𝑠𝑠 𝑜𝑜−𝑜𝑜𝑜𝑜 ,

𝜕𝜕𝜌𝜌𝑠𝑠

𝜕𝜕𝑡𝑡 =𝜕𝜕𝜌𝜌𝑠𝑠

𝜕𝜕𝑝𝑝𝜕𝜕𝑝𝑝𝜕𝜕𝑡𝑡 +

𝜕𝜕𝜌𝜌𝑠𝑠

𝜕𝜕𝑇𝑇𝜕𝜕𝑇𝑇𝜕𝜕𝑡𝑡 = 𝛽𝛽𝑠𝑠𝑡𝑡𝜌𝜌𝑠𝑠

𝜕𝜕𝑝𝑝𝜕𝜕𝑡𝑡 − 𝛽𝛽𝑠𝑠𝑜𝑜𝜌𝜌𝑠𝑠



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�𝑛𝑛 𝜌𝜌𝑤𝑤𝑙𝑙 − 𝜌𝜌𝑤𝑤𝑔𝑔 𝜕𝜕𝑆𝑆𝑙𝑙

𝜕𝜕𝑇𝑇 − 1 − 𝑛𝑛 𝑆𝑆𝑙𝑙𝜌𝜌𝑤𝑤𝑙𝑙 + 𝑆𝑆𝑔𝑔𝜌𝜌𝑤𝑤𝑔𝑔 𝛽𝛽𝑠𝑠𝑜𝑜 − 𝑛𝑛𝑆𝑆𝑙𝑙𝛽𝛽𝑤𝑤𝑜𝑜𝜌𝜌𝑤𝑤𝑙𝑙

water:𝜕𝜕 𝜙𝜙𝑙𝑙𝜌𝜌𝑙𝑙𝜔𝜔𝑤𝑤𝑙𝑙

𝜕𝜕𝑡𝑡+ 𝛻𝛻 � 𝜙𝜙𝑙𝑙𝜌𝜌𝑙𝑙𝜔𝜔𝑤𝑤𝑙𝑙 𝒗𝒗𝑙𝑙 + 𝛻𝛻 � 𝒋𝒋𝑤𝑤𝑙𝑙

𝑤𝑤𝑠𝑠𝑠𝑠𝑟𝑟𝑟𝑟 𝑚𝑚𝑖𝑖 𝑙𝑙𝑚𝑚𝑙𝑙𝑚𝑚𝑚𝑚𝑑𝑑 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟

+𝜕𝜕 𝜙𝜙𝑔𝑔𝜌𝜌𝑔𝑔𝜔𝜔𝑤𝑤

𝑔𝑔

𝜕𝜕𝑡𝑡+ 𝛻𝛻 � 𝜙𝜙𝑔𝑔𝜌𝜌𝑔𝑔𝜔𝜔𝑤𝑤

𝑔𝑔𝒗𝒗𝑔𝑔 + 𝛻𝛻 � 𝒋𝒋𝑤𝑤𝑔𝑔

𝑤𝑤𝑠𝑠𝑠𝑠𝑟𝑟𝑟𝑟 𝑚𝑚𝑖𝑖 𝑔𝑔𝑠𝑠𝑠𝑠 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟

+ ⏟0𝑤𝑤𝑠𝑠𝑠𝑠𝑟𝑟𝑟𝑟 𝑚𝑚𝑖𝑖 𝑠𝑠𝑜𝑜𝑙𝑙𝑚𝑚𝑑𝑑 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟

= 0


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dry air:

𝜕𝜕 𝜙𝜙𝑙𝑙𝜌𝜌𝑙𝑙𝜔𝜔𝑠𝑠𝑙𝑙

𝜕𝜕𝑡𝑡+ 𝛻𝛻 � 𝜙𝜙𝑙𝑙𝜌𝜌𝑙𝑙𝜔𝜔𝑠𝑠𝑙𝑙 𝒗𝒗𝑙𝑙 + 𝛻𝛻 � 𝒋𝒋𝑠𝑠𝑙𝑙

𝑑𝑑𝑚𝑚𝑠𝑠𝑠𝑠𝑜𝑜𝑙𝑙𝑣𝑣𝑟𝑟𝑑𝑑 𝑑𝑑𝑟𝑟𝑑𝑑 𝑠𝑠𝑚𝑚𝑟𝑟 𝑚𝑚𝑖𝑖 𝑙𝑙𝑚𝑚𝑙𝑙𝑚𝑚𝑚𝑚𝑑𝑑 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟

+𝜕𝜕 𝜙𝜙𝑔𝑔𝜌𝜌𝑔𝑔𝜔𝜔𝑠𝑠

𝑔𝑔

𝜕𝜕𝑡𝑡+ 𝛻𝛻 � 𝜙𝜙𝑔𝑔𝜌𝜌𝑔𝑔𝜔𝜔𝑠𝑠

𝑔𝑔𝒗𝒗𝑔𝑔 + 𝛻𝛻 � 𝒋𝒋𝑠𝑠𝑔𝑔

𝑑𝑑𝑟𝑟𝑑𝑑 𝑠𝑠𝑚𝑚𝑟𝑟 𝑚𝑚𝑖𝑖 𝑠𝑠𝑜𝑜𝑚𝑚𝑙𝑙 𝑣𝑣𝑜𝑜𝑚𝑚𝑑𝑑𝑠𝑠+ ⏟0

𝑑𝑑𝑟𝑟𝑑𝑑 𝑠𝑠𝑚𝑚𝑟𝑟 𝑚𝑚𝑖𝑖 𝑠𝑠𝑜𝑜𝑙𝑙𝑚𝑚𝑑𝑑 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟= 0

�𝑛𝑛𝜌𝜌𝑠𝑠 𝐻𝐻 − 1𝜕𝜕𝑆𝑆𝑙𝑙

𝜕𝜕𝑇𝑇 + 𝑛𝑛𝜌𝜌𝑠𝑠𝑆𝑆𝑙𝑙𝜕𝜕𝐻𝐻𝜕𝜕𝑇𝑇 − 1 − 𝑛𝑛 𝜌𝜌𝑠𝑠 𝑆𝑆𝑔𝑔 + 𝐻𝐻𝑆𝑆𝑙𝑙 𝛽𝛽𝑠𝑠𝑜𝑜


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Thermal:

Φ𝑝 = 𝜙𝜙𝑚𝑚𝜌𝜌𝑚𝑚𝜔𝜔𝑘𝑘𝑚𝑚 𝐸𝐸𝑜𝑜𝑘𝑘𝑚𝑚heat capacity:

𝐸𝐸𝑜𝑜𝑘𝑘𝑚𝑚 = 𝑐𝑐𝑘𝑘𝑚𝑚 𝑇𝑇𝑘𝑘𝑚𝑚 − 𝑇𝑇𝑘𝑘𝑜𝑜𝑚𝑚

Φ𝑝 = 1 − 𝑛𝑛 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝑛𝑛 𝐻𝐻𝑆𝑆𝑙𝑙 + 𝑆𝑆𝑔𝑔 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝑛𝑛𝑆𝑆𝑙𝑙𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 + 𝑛𝑛𝑆𝑆𝑔𝑔𝜌𝜌𝑤𝑤𝑔𝑔𝑐𝑐𝑤𝑤

𝑔𝑔 𝑇𝑇 − 𝑇𝑇𝑜𝑜

heat flux:𝒒𝒒𝑝 = �𝒒𝒒𝑜𝑜

𝑐𝑐𝑜𝑜𝑖𝑖𝑑𝑑𝑚𝑚𝑐𝑐𝑠𝑠𝑚𝑚𝑜𝑜𝑖𝑖+ 𝜌𝜌𝑚𝑚 𝜔𝜔𝑘𝑘𝑚𝑚 𝐸𝐸𝑜𝑜𝑘𝑘𝑚𝑚 𝒒𝒒𝑚𝑚

𝑐𝑐𝑜𝑜𝑖𝑖𝑣𝑣𝑟𝑟𝑐𝑐𝑠𝑠𝑚𝑚𝑜𝑜𝑖𝑖 𝑏𝑏𝑑𝑑 𝑙𝑙𝑚𝑚𝑙𝑙𝑚𝑚𝑚𝑚𝑑𝑑 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟

+ 𝐸𝐸𝑜𝑜𝑘𝑘𝑚𝑚 𝒋𝒋𝑤𝑤𝑚𝑚𝑐𝑐𝑜𝑜𝑖𝑖𝑣𝑣𝑟𝑟𝑐𝑐𝑠𝑠𝑚𝑚𝑜𝑜𝑖𝑖 𝑏𝑏𝑑𝑑 𝑔𝑔𝑠𝑠𝑠𝑠 𝑡𝑡𝑝𝑠𝑠𝑠𝑠𝑟𝑟

𝒒𝒒𝑝 = −λ𝑜𝑜𝛻𝛻𝑇𝑇 + 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝜌𝜌𝑤𝑤𝑔𝑔𝑐𝑐𝑤𝑤

𝑔𝑔 𝒒𝒒𝒈𝒈 + 𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 + 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠𝐻𝐻 𝒒𝒒𝒍𝒍 𝑇𝑇 − 𝑇𝑇𝑜𝑜 + 𝑐𝑐𝑤𝑤𝑔𝑔 − 𝑐𝑐𝑠𝑠 𝒋𝒋𝑤𝑤



34


Energy balance: very complex

𝛻𝛻 � 𝒒𝒒𝒉𝒉= −λ𝑜𝑜𝛻𝛻 � 𝛻𝛻𝑇𝑇 + 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝜌𝜌𝑤𝑤

𝑔𝑔𝑐𝑐𝑤𝑤𝑔𝑔 𝑇𝑇 − 𝑇𝑇𝑜𝑜 𝛻𝛻 � 𝒒𝒒𝑔𝑔 + 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝜌𝜌𝑤𝑤

𝑔𝑔𝑐𝑐𝑤𝑤𝑔𝑔 𝒒𝒒𝒈𝒈 � 𝛻𝛻𝑇𝑇

+ 𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 + 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠𝐻𝐻 𝑇𝑇 − 𝑇𝑇𝑜𝑜 𝛻𝛻 � 𝒒𝒒𝑙𝑙 + 𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 + 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠𝐻𝐻 𝒒𝒒𝑙𝑙 + 𝑐𝑐𝑤𝑤𝑔𝑔 − 𝑐𝑐𝑠𝑠 𝒋𝒋𝑤𝑤

𝑔𝑔 � 𝛻𝛻𝑇𝑇+ 𝑐𝑐𝑤𝑤

𝑔𝑔 − 𝑐𝑐𝑠𝑠 𝑇𝑇 − 𝑇𝑇𝑜𝑜 𝛻𝛻 � 𝒋𝒋𝑤𝑤𝑔𝑔

𝐴𝐴 = −𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝐻𝐻𝑆𝑆𝑙𝑙𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝑆𝑆𝑔𝑔𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝑆𝑆𝑙𝑙𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 + 𝑆𝑆𝑔𝑔𝜌𝜌𝑤𝑤𝑔𝑔𝑐𝑐𝑤𝑤


𝐵𝐵 = 1 − 𝑛𝑛 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 𝑇𝑇 − 𝑇𝑇𝑜𝑜

𝐶𝐶 = 𝐻𝐻𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 − 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 − 𝜌𝜌𝑤𝑤𝑔𝑔𝑐𝑐𝑤𝑤


𝐷𝐷 = 𝑛𝑛 𝐻𝐻𝑆𝑆𝑙𝑙𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝑆𝑆𝑔𝑔𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠 + 𝑆𝑆𝑙𝑙𝜌𝜌𝑤𝑤𝑙𝑙 𝑐𝑐𝑤𝑤𝑙𝑙 + 𝑆𝑆𝑔𝑔𝜌𝜌𝑤𝑤𝑔𝑔𝑐𝑐𝑤𝑤

𝑔𝑔 + 1 − 𝑛𝑛 𝜌𝜌𝑠𝑠𝑐𝑐𝑠𝑠Abed & Sołowski (2017)

35

Thermo-hydro-mechanical FE simulations

0,60

0,65

0,70

0,75

0,80

0,85

0,90

0,95

1,00

1,05

0 100 200 300 400 500 600 700

void

ratio

e[-]

isotropic net stress p [kPa]

Alonso et al. (1990)Current BBM implementation in Numerrin

Abed et al. (2016)

36


0

50

100

150

200

250

300

350

0,00 0,05 0,10 0,15 0,20 0,25 0,30

devi

ator

ic st

ress

q[k

Pa]

shear strain εq [-]

Alonso et al. (1990)

Current BBM implementation in Numerrin

Abed et al. (2016)

37



38

Replication of data from Jyväskylä University

Abed et al. (2016)

39


Abed & Sołowski, (2017)

Infiltration test, Villar (2005)

40



Infiltration test, Villar (2005)

41


No perfect match between codes due to different water vapour transport models

isothermal infiltration


42


non-isothermal infiltration


43


non-isothermal infiltrationthe effect of swelling on the water hydraulic conductivity


44

FE simulations: CIEMAT Mock-Up testExample: Simulation of CIEMAT Mock-Up test for 2500 days (Martin et al. 2006)The hydro-thermal coupling is based on the theory proposed by Philip & De Vries (1957).


45



46



47

Calculated relative humidity versus measurements

FE simulations: CIEMAT Mock-Up test

20

30

40

50

60

70

80

90

100

0 500 1000 1500 2000 2500

Rel

ativ

e hu

mid

ity [%

]

Time [days]

RH1 (0.22,1.0)RH2 (0.37, 1.0)RH3 (0.55,1.0)RH4 (0.7, 1.0)Aalto Code


48

Calculated temperature versus measurements


0

10

20

30

40

50

60

70

80

90

100

0 500 1000 1500 2000 2500

Tem

pera

ture

[Co ]

Time [days]

T (0.77, 1.185) T (0.58, 1.185)T (0.39, 1.185) T (0.22, 1.185)Aalto Code


49

Calculated swelling pressure versus measurements


0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 500 1000 1500 2000 2500

Rad

ial s

tres

s [kP

a]

Time [days]

Radial stress (0.667, 1.0)

Aalto Code


50


0

200

400

600

800

1000

1200

0 500 1000 1500 2000 2500

wat

er m

ass [

kg]

Time [days]

Water intake measurements

Aalto Code


Calculated water intake versus measurements

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FE simulations: CIEMAT Mock-Up testAalto Code prediction after a duration of 2500 days of the test

Temperature Degree of saturation Porosity

52

References:1- Martin, P. L., Barcala, J. M., & Huertas, F. (2006). Large-scale and long-term coupled thermo-hydro-mechanic experiments with bentonite: the FEBEX mock-up test. Journal of Iberian geology, 32(2), 259-282.

2- Philip, J. R. and D. De Vries.1957. Moisture movement in porous material under temperature gradients. Transactions of the American Geophysical Union, 38 (2): 222-232.

3- Abed, A. A., Sołowski, W. T. (2017). A study on how to couple thermo-hydro-mechanical behaviourof unsaturated soils: Physical equations, numerical implementation and examples. Computers and Geotechnics 92, 132-155

4- Abed, A. A., Sołowski, W. T. (2017).Validation of a Fully Coupled THM Finite Element Code: Simulation of CIEMAT Mock-Up Test. Submitted to 15th IACMAG, 15th International Conference of the International Association for Computer Methods and Advances in Geomechanics (15th IACMAG) on October 19-23, 2017 in Wuhan, China.

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Outline

I. Introduction & overview (15 min)II. Research at Aalto

I. THMC modelling of bentonite / swelling claysII. Investigation of effects of salinity on bentonite

54

Water retention behaviour of MX-80 bentonite

Aim: find out what is the influence of salinity on water retention behaviour of MX-80 bentonite

Lahtinen et al. 2016

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Water retention behaviour of MX-80 bentoniteAim: find out what is the influence of salinity on water retention behaviour of MX-80 bentonite

Yang & Sołowski (in preparation)

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0

10

20

30

40

50

60

70

80

90

100

0 20 40 60 80 100 120 140 160 180

satu

ratio

n %

total suction MPa

0M-FP-total suction

1M-FP-total suction

2M-FP-total suction

5M-FP-total suction

0M-WP4C-total suction




57




58

Water retention behaviour of MX-80 bentoniteAim: find out what is the influence of salinity on water retention behaviour of MX-80 bentonite

Yang & Sołowski (in preparation)1,50

1,55

1,60

1,65

0 10 20 30 40 50 60 70 80 90 100

dry

dens

ity

saturation

0M-wp4c new

1M -wp4c-new

2M-new

5m-new

0

10

20

30

40

50

60

70

80

90

100

0 20 40 60 80 100 120 140 160 180sa

tura

tion

%total suction MPa

0M-FP-total suction

1M-FP-total suction

2M-FP-total suction

5M-FP-total suction





1,50

1,52

1,54

1,56

1,58

1,60

1,62

1,64

1,66

1,68

0,0 0,2 0,4 0,6 0,8 1,0

dry

dens

ity, g

/cm

3

degree of saturation

0M-FPM 1M-FPM 2M-FPM5M-FPM 0M-WP4C 1M-WP4C2M-WP4C 5M-WP4C

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Microstructure characterization (note: issues in the test – higher pressureneeded! – work in progress)


60

Water retention behaviour of MX-80 bentoniteMicrostructure based model: Dieudonné et al. (2013)

PSD model after fitting on Boom clays experimental data (Dieudonné et al., 2013)


61

Water retention behaviour of MX-80 bentoniteMicrostrucure based model: Dieudonné et al. (2013)


Pore size distribution curve of Mx-80 bentonite (after Seiphoori et al, 2014)

62


PSD test and calibrated model for Mx-80 bentonite which has a degree of saturation of 0.62.


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Calibrated water retention curve of Mx-80 compared with the tests used for the calibration process.

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Calibrated water retention curve of Mx-80 compared with the test made by the Aalto University with the WP4C instrument (after Yang and Sołowski, in preparation)

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• Dieudonné et al. 2013 is now available in the FE code now, so calculations will follow

• Constitutive models which incorporate micro- and macrostructure are being implemented (or are available already) in the FE code

• Salinity effects are being implemented

• Better microstructural investigations of salinity effects are thought of

Thank you !!!

Presentation will be uploaded and available athttp://solowski.info and THEBES website

67

THEBESTHMC Behaviour of the Swelling Clay Barriers

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