04_mex.tex

\chapter{Model-Experiment-Exercises (MEX)}
\label{cha:mex}

\Authors{Bernhard Vowinckel, Thomas Frühwirt, Jobst Maßmann, Thomas Nagel, Mathias Nest, Daniel Pötschke, Christopher Rölke, Amir Sattari, Patrick Schmidt, Holger Steeb, Keita Yoshioka, Gesa Ziefle}

The basic idea of Model-Experiment-Exercises (MEX) is to link modelling and experimental works from the very beginning – i.e. in the conceptual phase. Due to the complexity of each part in the systems analysis, this combination is sometimes lost. Moreover, both models and experiments require highly sophisticated tools and equipment as well as highly specialized professionals, which also necessitate adequate measures and incentives for collaboration. GeomInt is introducing the MEX concept exactly for this purpose. Therefore, the following MEX studies occupy the largest part of the GeomInt book and feed most of the publications with research material.
\index{MEX Model-Experiment-Exercise}

\begin{wrapfigure}{l}{5cm}
\includegraphics[width=4.9cm]{figures/geomint-mex-a}
\caption{MEX concept}
\label{fig:mex-concept-generic}
\end{wrapfigure}
In order to illustrate the MEX concept, Fig. \ref{fig:mex-concept-generic} depicts the dependencies between laboratory (LAB) and field experiments (URL) as well as modelling work (MOD). Lab experiments (LAB) will be analysed by models (MOD) in order to calibrate parameters and validate them [1]. This step in the analysis loop should proof that the models are able to represent the experiments (validation). Models will be also used for planning experimental work in order to improve the general process understanding [2] (experimental design). Both lab experiments and models must be scaleable to field experiments [3].

\begin{figure}
\centering
\includegraphics[width=0.7\textwidth]{figures/geomint-mex-b.png}
\caption{MEX in WPs}
\label{fig:mex-concept-wps}
\end{figure}

The generic approach for systems analysis described above is applied to GeomInt through the individual work packages (WP1-3) linking experimental works in the laboratories (lab and field) and numerical modelling (Fig. \ref{fig:mex-concept-wps}). Due to the limited project time this is being demonstrated for selected cases. A specific challenge for the GeomInt project is the development and implementation of generic numerical methods which are able to simulated THM coupled processes for various rock types – ductile and brittle materials (thermodynamic consistency) with an emphasis of discontinuities. This is the concept of building GeomInt frameworks – experimental (see Chapter \ref{cha:exp}) and numerical platforms (see Chapter \ref{cha:num}).
\index{thermodynamic consistency}

Before WP related MEX are described, a prerequisite of two exercises dealing with bending test are introduced for granite and clay. Here the fracture process is initiated by external loads (i.e. not by fluid injection). These bending tests are providing important information on the elastic material behavior before fracturing the specimen (\MEXone). Moreover, for clay samples, particularly from sandy facies, the lamination of the material is largely influencing fracturing processes. A concept for a humidity controlled bending test is presented in \MEXthirteen~with is related to the planned CD-A experiment in Mt. Terri.

%\clearpage
%\begin{figure}[hbtp]
%\caption{Model-Experiment-Exercises (MEX) as of 27.12.2019}
%\centering
%\includegraphics[width=18cm,angle=90]{figures/mex-overview.png}
%\end{figure}

Fig. \ref{fig:mex-overview} illustrates an overview of the forthcoming Model-Experiment-Exercises (MEX) combining both theoretical work and experiments at various scales.
The MEX concept is the central synthesis element of GeomInt as it is directly linking models (MOD) with lab experiments (LAB) and paving the way towards the analysis of in-situ experiments (URL) (see also chapter \ref{cha:out}).

\clearpage

\begin{figure}[!ht]
\centering
\includegraphics[width=0.85\textwidth]{figures/geomint-mex-overview.png}
\caption{Overview of Model-Experiment-Exercises (MEX)}
\label{fig:mex-overview}
\end{figure}

MEX are organized mainly along the projects work packages (lines) as well as experiments (LAB/URL) and various modelling approaches (columns) (Tab. \ref{tab:mex-overview}).

\begin{table}[!hb]
\footnotesize
\centering
\caption{Model-Experiment-Exercises (MEX) matrix}
\label{tab:mex-overview}
\begin{tabular}{|C{0.7cm}|L{3.7cm}|C{0.7cm}|C{0.7cm}|C{0.7cm}|C{0.7cm}|C{0.7cm}|C{0.7cm}|} 
\hline 
\rowcolor{cyan!50}
MEX & TOP & EXP & \multicolumn{5}{c|}{MOD} \\ 
\hline
\rowcolor{cyan!50}
WP &  &  & LEM & DEM & FEM & HDF & FFS \\ 
\hline \hline
%-------------------
0-1a & Bending fracture test & LIT & \cellcolor{lightgray} & \cellcolor{lightgray}  & \cellcolor{lightgray} &  &  \\ 
\hline 
0-1b & Bending fracture test (aniso) & \cellcolor{lightgray} LAB & \cellcolor{lightgray} & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  \\ 
\hline 
0-2 & Humidity controlled bending & \multicolumn{6}{c|}{Concept} \\ 
\hline \hline
%-------------------
1-1a & Swelling of clay & \cellcolor{lightgray} LAB & \cellcolor{lightgray} & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  \\ 
\hline
1-1b & Swelling of clay & \cellcolor{lightgray} LAB &  & \cellcolor{lightgray} &  &  &  \\ 
\hline
1-2 & Shrinkage of clay & \cellcolor{lightgray} LAB & \cellcolor{lightgray} & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  \\ 
\hline
1-3 & Desiccation of clay & \multicolumn{6}{c|}{Concept} \\ 
\hline
1-4 & CD/LP experiment & \cellcolor{lightgray} URL &  &  & \cellcolor{lightgray} &  &  \\ 
\hline \hline
%-------------------
2-1a & Pressure driven percolation & LIT & \cellcolor{lightgray} & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  \\ 
\hline
2-1b & Pressure driven percolation & \cellcolor{lightgray} LAB & \cellcolor{lightgray} & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  \\ 
\hline
2-2 & Healing / closure & \cellcolor{lightgray} LAB & \cellcolor{lightgray} & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  \\ 
\hline
2-3 & Compressible fluids & LIT & \cellcolor{lightgray} & \cellcolor{lightgray} &  &  &  \\ 
\hline
2-4 & URL Springen & \cellcolor{lightgray} URL &  & \cellcolor{lightgray} &  &  &  \\ 
\hline \hline
%-------------------
3-1 & CNL test & \cellcolor{lightgray} LAB &  &  &  &  & \cellcolor{lightgray} \\ 
\hline
3-2 & CNS test & \cellcolor{lightgray} LAB &  &  &  &  & \cellcolor{lightgray} \\ 
\hline
3-3 & Cyclic loading & \cellcolor{lightgray} LAB &  &  &  & \cellcolor{lightgray} &  \\ 
\hline \hline
%-------------------
\end{tabular}
\tiny
Legende: (EXP) experimental data from literature (LIT), LAB and field experiments (URL). Various modelling approaches (MOD): lattice (LEM), distinct (DEM), finite elements (FEM), hybrid-dimensional (HDF), and forces on fracture surfaces (FFS) are developed and compared against experimental results.
\end{table}
\normalsize

\clearpage
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\input{04_mex01}
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\input{04_mex_0-1b}
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\input{04_mex13}
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\section*{WP1: Pathways through swelling/shrinking processes (clay rock)}
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\input{04_mex05}
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\input{04_mex06}
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\input{04_mex12}
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\input{04_mex10}
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\section*{WP2: Pathways through pressure-driven percolation (clay/rock salt)}
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\input{04_mex02}
\clearpage
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\input{04_mex_2-1b}
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\input{04_mex03}
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\input{04_mex04}
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\input{04_mex11}
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\section*{WP3: Pathways through stress redistribution (crystalline rock)}
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\input{04_mex07_CNL.tex}
\clearpage
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\input{04_mex08}
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\input{04_mex09}
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