\chapter{Use of the \MacroStabilityKernel} \label{sec:UseStabKernel}

For stabilily calculation the DAM engine uses the \MacroStabilityKernel.
This use is restricted to the options described in this chapter.

\section{Model}\label{sec:Model}
The DAM Engine must be able to make calculations with following models:
		\begin{itemize}
		\item Bishop
		\item Uplift Van
		\item Bishop/Uplift Van
	\end{itemize}
	
All models are available for inwards stability. For outward stability only Bishop is used.
	
The choice of the model is a demand of the client:\\
DAM Client can demand Bishop, Uplift Van or combination Bishop/Uplift Van.\\
	
\subsection{Combination model Bishop/Uplift Van}
\label{sec:CombinationBishopUpliftVan}

The combination model Bishop-Uplift Van gives three results:
\begin{enumerate}
	\item Bishop
	\item Uplift Van\newline
	The client provides a requested uplift safety.	The Uplift Van calculation is made when this requested uplift safety factor is lower than the calculated uplift safety factor (for definition see 
	\autoref{sec:UpliftCalculation}). Otherwise the result is 'not calculated'.
	\item Normative result (lowest safety factor) of both.
\end{enumerate}

\section{Slip plane definition and calculation area}\label{sec:PlaneDefinitionAndCalculationArea}
		
\subsection{Search method}
For both models Bishop and Upift Van, a brute force search method is available. With this method the grids are moved automatically as long as the center point(s) for the found minimum value is on the edge of the search grid 
(with a maximum of 50 moves). 
See FD (\citep{MacroStabilityReqAndFD22}) of \MacroStabilityKernel for more information on this.

For model Uplift Van, next to brute force the Bee Swarm search method is offered. Based on a set of steering parameters, this method finds a minimum based on the Bee Swarm method (for more information on this see the FD (\citep{MacroStabilityReqAndFD22}) of \MacroStabilityKernel).

For the Bishop/Uplift Van combination model, for Bishop the brute force method will always be used whereas for the Uplift Van part the choice between brute force and Bee Swarm is given.

\subsection{Grid generation}
\label{sec:GridGeneration}
	
For the models Bishop and Uplift Van a calculation grid must be generated.
There are two options:
\begin{enumerate}
	\item automatic generation (Automatic)
	\item user defined generation (Specified)
\end{enumerate}

Ad 1 Automatic generation\newline
See FD (\citep{MacroStabilityReqAndFD22}) of \MacroStabilityKernel.

Ad 2 Client defined generation\newline
The client defines the dimensions; number of grid points and distance between the points. The \ProgramName defines the position of the grid depending on the characteristic points:
For Bishop and for the active grid of Uplift Van the left (outside) bottom corner is situated at the surface line in the middle of the crest (distance between outer- and inner crest). The right bottom corner of the passive grid of Uplift Van is situated above the most right x co-ordinate where uplift occurs. With the restriction that the left bottom corner can not be situated left of the x co-ordinate of the DikeToePolder.	
	
\subsection{Tangent lines generation}
\label{sec:TangentLinesGeneration}

For the Bishop model only automatic generation is used.\newline
The tangent lines are placed from the minimum Z-value of the surface line until 0.5 m below the upper geometry point of the lowest aquifer. The distance between the tangent lines is 0.25 m.

For Uplift Van there are two client defined methods\newline
Distance defined\newline
For Uplift Van the client must provide the distance between the tangent lines.
The lower tangent line is always situated 0.5 m below the boundary of the upper aquifer. The tangent lines are drawn with the given distance until the minimum Z value of the passive grid.\newline
On boundary - Op laagscheidingen (default)\newline
On every boundary of the subsoil layer.

\subsection{Calculation area}
\label{sec:CalculationArea}
For the model Horizontal balance a calculation area must be defined:
\begin{table*}[h]
	\centering
		\begin{tabular}{|p{50mm}|p{90mm}|} \hline
			\textbf{Parameter} & \textbf{Default value}\\ \hline
			X co-ordinate left side [m]& x co-ordinate DikeTopAtRiver\\ \hline
			X co-ordinate right side [m]& x co-ordinate DikeToeAtPolder\\ \hline
			Highest slip plane level [m]& Z value PL4 or PL3 (when one aquifer present) at x co-ordinate DikeToeAtRiver \\ \hline
			Lowest slip plane level [m]& Maximum Z value of top aquifer within calculation area\\ \hline
			Number of planes in the slip plane level [-]& 12\\ \hline
		\end{tabular}
	\caption{Calculation area for horizontal balance}
	\label{tab:CalcutlationArea}
\end{table*}


\section{Shear strength model}\label{sec:ShearStrengthModel}
The DAM engine must be able to make stability calculations with following shear strength models:
	\begin{itemize}
		\item MohrCoulomb
		\item SHANSEP
		\item SigmaTauTable
		\item SuTable
	\end{itemize}	
	This shear strength models are defined in the soil parameters per layer.

\section{Calculation options}\label{sec:CalculationOptions}
D-Geostability offers different following calculation options. \ProgramName uses for the following settings the defaults of D-Geo Stability 18.1:
		
\begin{itemize}
	\item Requested number of slices: default D-Geo Stability
		\item Minimum slip plan length: default D-Geo Stability
	\item Start value safety factor: default D-Geo Stability
  \item Minimum x-entrance used: default D-Geo Stability
\end{itemize}

The following settings can be defined by the client:
\begin{itemize}
	\item Minimum circle depth
	\item Maximum x-entrance
\end{itemize}

The maximum x-entrance used is not directly client defined. The client provides a Forbidden zone and the \ProgramName calculates a maximum x-entrance via a method described in \autoref{sec:ForbiddenZone}.

\subsubsection{Forbidden zone }\label{sec:ForbiddenZone}
Forbidden zone is an option to define a forbidden zone for the entrance point of the slip plane.
The forbidden zone is situated to the rigth side of a certain x co-ordinate. This x co-ordinate is defined by the \textsl{ForbiddenZoneFactor}. Xlocal;forbidden zone WF =(Xlocal;DikeTopAtPolder) + ForbiddenZoneFactor*(Xlocal;DikeToeAtPolder - Xlocal;DikeTopAtPolder)
A forbidden zone is used when \textsl{ZoneType} = ForbiddenZone (see \autoref{tab:ForbiddenZoneFactor}). 

\begin{table*}[ht]
	\centering
		\begin{tabular}{|p{35mm}|p{75mm}|} \hline
			ForbiddenZonefactor & maximum x-entrance\\ \hline
			0 & x co-ordinate DikeTopAtPolder\\ \hline
			1 & x co-ordinate DikeToeAtPolder\\ \hline
		\end{tabular}
	\caption{Forbidden zone factor}
	\label{tab:ForbiddenZoneFactor}
\end{table*}

In a picture:

\begin{figure}[H]
	\centering
		\includegraphics[width=0.95\textwidth]{pictures/ForbiddenZoneFactor.png}
	\caption{Forbidden zone factor}
	\label{fig:ForbiddenZoneFactor}
\end{figure}

\section{Traffic load Degree of consolidation}\label{sec:TLDegOfCo}
The traffic load degree of consolidation is a material parameter. 
In the UI the import of the traffic load degree of consolidation is done per material via soils.csv.
