Calligra for day to day work.

[woodsmoke]

The whole thing about "But it isn't MS compatible." or "It doesn't allow spacing over with space bar".

Just irritate me to no end.

I use Calligra for "day to day work".

AND I use it for MS compatible work.

I also use it for very specialized work, such as making Presentations for my lectures. And the export is MS compatible. IF you do not do any fancy formatting...

And I hate to say it.......if you need to have fancy formatting on a Presentation slide then you do not "get" how Presentations are supposed to work.

Simple text, LARGE text, one idea per slide, you can have thousands of them, and one image.

I used to "trans"port through LO but do not now so do.

For "text processing" I use Arial as font, save as .odt and can send it to the college and Word recognizes it. I may have to do some kind of formatting stuff there but

I can format it there or I can format it here ....it takes the same amount of time.

And anybody who does a lot of "text work" knows that in a "word processor" environment.........do the formatting after you have all the text in.

I also use it for electronic book publishing.

So why this post?

Due to my changed financial circumstances, I have lost a lot of money, I am applying for any kind of part time job like a house a' fire, I do not let the grass grow under my feet.

I was getting fuel and there was a "company van" in front of me which is a mid-level "retailer/wholesaler" of filtration equipment to various industries, technical stuff, not pencils and computers.

So I asked the driver if the company was looking for part time help.

Won't get into all that but called the main office, in another state, the guy said they are not hiring but..... send a resume.

I walked into the apartment,

Turned the monitor on.

clicked the icon for Calligra words and then Sheets in the launcher widget.

Navigated to my resume which is PAGES long, opened recent documents for resume letter, rearranged the order of the "one side one sheet" introductory page, copied and pasted pertinent other infommation, deleted some.

Went to sheets which holds my MANY people who will recommend me with their phone numbers, addys etc. not that I am bragging but I have that many people who will recommend me....so I use a spreadsheet.

Copied and pasted the appropriate ones into that part of the resume letter.

Since this company deals with hight pressure filtrations systems I went to GIMP, opened a pic of me teaching my physical science class about the two stages, one high pressure and one low pressure, of SCUBA air systems changed the size and resolution, exported to .png and inserted the image below the normal image that I have on the introductory page. (even put a "shadow" on it).

Saved with appropriate company exported to .pdf.

Opened Kontact, and e-mail, added the company as a contact, made a new e-mail attached .pdf of resume and .pdf of transcripts.

selected to get a notifiicaton from the company that they had opened the e-mail,

Fired it off.

I ....would......have put the .pdfs into a .zip file but.........I found out that MOST people in a windoze centric world have NO CLUE about how to open a zip file...

begin rant ----I mean I............KNEW THAT............ within a few months of being on the net back in Windblows 2000. duuh. But anyway --- rant end

But.... half an hour and I was done... ground some coffee beans and am typing this.

Calligra works for day to day work.

Does MIcrosith work for a million dollar cad program that requires a special file..........ummm NO...... does MS work with many apple products....um no..

so........

For people with open minds who truely want to have an office suite which works ERGONOMICALLLY with your wrist, and one that works for day to day applications...

Install Calligra.

Try it as a default to see if it meets your needs.

If it does not then all it takes is opening synaptic and uninstalling....you can do that while watching a you-tube video.

But.........you might like it.

KInda like Bill Murray..... not! lol

woodsmoke

[NickStone]

Yes I agree with you about exporting documents to pdf format if you want to send the document to someone. Most (if not all) computers users have a app to display pdf documents. You do not need a word processor that saves as a Word document to share it with Windows users, just export to pdf.

[Feathers McGraw]

Cool!

For something like a CV (where presentation is really important) or a dissertation (very long) I quite like LaTeX (usually use TeXworks): making changes to large documents is so much easier because images float, so if you go back and add a paragraph near the start of the document you're not left with 100 half pages where your images used to be!

Does exactly what you tell it to do, and no more. None of this "we think you wanted to do X" rubbish you get with WYSIWYG editors!

And one last thing... anything typeset in Computer Modern looks true, even if it isn't, which could be very useful for CVs if some of the things I've heard are true!

[richb]

What is the learning curve for LaTex?

[Feathers McGraw]

I learned it in a hurry in a couple of weeks at uni. Pretty easy really, basic documents are really simple, and you can be clever if you like. Good for procrastinating!

Once you have found a style you like, you can just copy and paste the bit before begin{document} and comment the bits you don't want this time (some of the packages called at the start probably aren't used).

The basics are pretty similar to HTML.

The most annoying thing is tables, but you can export those from gnumeric instead of creating them by hand if you like.

Sample PDF attached, here is the source... sorry it's so long, I chose a document that had lots of different bits in it (some maths, images, tables, headers, footers... and this happened to get me 98%!):

\documentclass[a4paper,12pt,titlepage,oneside]{article} %fleqn aligns all equations to the left
%\usepackage{txfonts} %IMPORTANT: clash with amsmath %use for times new roman and similar fonts
%\renewcommand{\familydefault}{\rmdefault} %\sfdefault for sans-serif; \rmdefault for times new roman; comment line AND txfonts package for computer modern
\author{Sam Hobbs}
\title{ENGM224\\Geotechnical Engineering 2\\Reinforced Soil Wall Design}

\usepackage{geometry}
%\geometry{pass} %disables all geometry options and calculations except verbose and showframe
\geometry{left=3.17cm,right=2.54cm,top=2.54cm,bottom=2.54cm}
%\geometry{showframe} %shows layout border lines

\usepackage{amsmath}% IMPORTANT!! clash with txfonts. %allows \begin{gather} and \begin{align} for equations (second one aligns equations about equals sign) ... \begin{gather*} and \begin{align*} do the same but with no equation nos

\usepackage{xcolor}

\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
%\usepackage{sidecap}
\usepackage{rotating}

\usepackage{fancyref}

\usepackage[section]{placeins}%places a float barrier at the beginning of each section so pictures never float too far.

\usepackage{wrapfig}

\usepackage{tabularx}
\usepackage{tabulary}%for balancing column widths so there is less blank space.

\usepackage{siunitx}

\usepackage{comment}

\usepackage{xfrac}%allows use of sideways fractions using \sfrac

\usepackage{longtable}%allows tables to span across multiple pages

\usepackage{multicol}%allows multiple columns for part of a page. If using floats use \begin{figure*} to span all columns


%\usepackage{natbib} % not compatible with biblatex but natbib commands can be used with the option "natbib=true"
%\bibliographystyle{plainnat}

\usepackage[backend=biber,citestyle=authoryear,bibstyle=authoryear,natbib=true]{biblatex}
\bibliography{../Sources.bib}

\usepackage{fancyhdr}
\pagestyle{fancy}

%title info is deleted after \maketitle so this allows a running author to be used so that it can be put into the footer
\makeatletter
\let\runauthor\@author
\def\runtitle{Reinforced Soil Wall Design}
\makeatother

\headheight=30pt


%\begin{comment} %use this lot for single sided
\lhead{\raisebox{-0.5\height}{\includegraphics[width=30mm]{../header}}}
\chead{\runtitle}
\rhead{Sam Hobbs}
\lfoot{\leftmark}
\rfoot{\thepage}
\cfoot{}
\renewcommand{\headrulewidth}{0pt}%headrulewidth makes a line of width 0.4pt separating the body from the body
\renewcommand{\footrulewidth}{0pt}
%\end{comment}

\begin{comment} %use this lot for double sided
\fancyhead{}
\fancyhead[RO,LE]{\raisebox{-0.5\height}{\includegraphics[width=30mm]{../header}}}
\fancyhead[LO,RE]{Sam Hobbs}
\chead{\runtitle}
\fancyfoot[RO,LE]{\thepage}
\fancyfoot[LO,RE]{\leftmark}
\cfoot{}
\renewcommand{\headrulewidth}{0pt}
\renewcommand{\footrulewidth}{0pt}
\end{comment}


%\institute{University of Surrey}%not working, look me up













\begin{document}
\maketitle
\newpage
\setcounter{page}{1}
\pagenumbering{roman}
\tableofcontents

\newpage
\listoffigures

\listoftables


\newpage
\setcounter{page}{1}
\pagenumbering{arabic}













\section{Introduction}
\def\runauthor{Sam Hobbs}
This report sets out the proposed design for a reinforced soil wall that will form part of a motorway embankment, with a crest height of \SI{10}{m} above existing ground level. The wall will be situated on gravelly clay, constructed using sand fill reinforced with Tensar polymer geogrids, and backfilled with clay. A section view of the proposed design is shown in \fref{fig:section}.

\begin{figure}[h!tb]
\centering
\includegraphics[width=\textwidth]{Section}
\caption{Section view through one side of the motorway embankment showing the reinforced soil retaining wall.\label{fig:section}}
\end{figure}




\section{Design Data}
This section presents the input data used in the calculations.

\FloatBarrier
\subsection{Soil Properties}
Three different soil types are present within the design:
\begin{enumerate}
\item Foundation Soil (gravelly clay)
\item Wall fill (sand)
\item Backfill behind wall (clay)
\end{enumerate}

\noindent The properties of these three soils are given in \fref{tab:soil}.

\begin{table}[h!tb]
\centering
\begin{tabular}{|l|c|c|c|c|}
\hline
\textbf{Soil Type}			& $\phi '$		&$c'$			&$\gamma$	&$q_{safe}$\\
				&($^{\circ}$)	&(\si{kN m^{-2}})	&(\si{kN m^{-3}})	&(\si{kN m^{-2}})\\ \hline
Wall Fill (sand)				&31			&0				&18.5		&N/A 	\\ \hline
Back fill (clay)				&23			&0				&19.5		&N/A 	\\ \hline
Foundation Soil (gravelly clay)	&27			&0				&N/A			&250		\\ \hline
\end{tabular}
\caption{Soil properties and parameters.\label{tab:soil}}
\end{table}



\FloatBarrier
\subsection{Wall Dimensions and Loading}
The finished embankment will consist of a reinforced soil wall with a vertical face underlying a slope of gradient 3:1, up to the final level of 10m above current ground level (refer to \fref{fig:section}).

For design purposes, the vertical section of wall will be considered as the wall itself, and the soil overlying the top of this will be considered as a surcharge (i.e. any soil above \SI{7}{m} on \fref{fig:section}). The geometry of the overlying soil means that it is sensible to treat it as two separate surcharges: a triangle for the slope, and a rectangle for the flat section further away from the wall. The values for these surcharges are shown in \fref{tab:surcharge}.

\begin{table}[h!tb]
\begin{tabulary}{\textwidth}{|l|C|C|C|}
\hline
\textbf{Name}		&\textbf{Height \si{m}}	&\textbf{Specific Weight of Soil \si{kN m^{-3}}}	&\textbf{Pressure \si{kN m^{-2}}} \\ \hline
Surcharge 1 (triangle)	&1.5				&19.5			&29.25		\\ \hline
Surcharge 2 (rectangle)	&3.0				&19.5			&58.50		\\ \hline
\end{tabulary}
\caption{Calculation of soil surcharge pressures.\label{tab:surcharge}}
\end{table}

As \SI{500}{mm} of the gravelly clay is to be removed prior to construction to ensure that the soil underlying the wall is not weathered, the foundation level is \SI{0.5}{m} below the existing ground level and the effective height of the wall is \SI{7.5}{m}.

\FloatBarrier
\subsection{Tensar Polymer Geogrid Properties}
Two different types of polymer geogrid are available for the design. Their minimum installed long-term strength ($P_d$) and interaction coefficients ($\alpha_p$ , $\alpha_s$) are shown in \fref{tab:geogrid}.

\begin{figure}[h!tb]
\centering
\includegraphics[width=\textwidth]{Geogrid_properties}
\caption{RE55 and RE80 geogrid properties \citep{TENSAR10}.\label{fig:Geogrid_properties}}
\end{figure}

\begin{table}[h!tb]
\centering
\begin{tabular}{|l|c|c|c|}
\hline
			& $P_d$			&$\alpha_p$		&$\alpha_s$		\\
			&(\si{kN m^{-1}})	&\emph{constant}	&\emph{constant}	\\ \hline
\textbf{RE55}	&14.7			&0.9				&0.85			\\ \hline
\textbf{RE80}	&22.0			&0.9				&0.85			\\ \hline
\end{tabular}
\caption{Tensar polymer geogrid properties for design.\label{tab:geogrid}}
\end{table}


\newpage
\section{Calculations}
In order to verify the retaining wall's stability, it will be checked for failure in the following states:
\begin{itemize}
\item Global stability:
\begin{itemize}
\item Sliding (\fref{sec:sliding}).
\item Overturning (\fref{sec:overturning}).
\item Bearing (\fref{sec:bearing}).
\end{itemize}
\item Internal Stability
\begin{itemize}
\item Tensile failure of geogrid (\fref{sec:tension}).
\item Wedge pullout failure (\fref{sec:wedge}).
\end{itemize}
\end{itemize}
\noindent Slip failure will not be considered in the design.

\subsection{Earth Pressure Coefficients}
Using Rankine's theory of earth pressure, the active earth pressure coefficient $K_a$ can be calculated using \fref{eq:ka} \citep{CRAIG04}:

\begin{equation}
K_a = \frac{1 - \sin{\phi}}{1 + \sin{\phi}}
\label{eq:ka}
\end{equation}

\noindent Therefore, the active earth coefficients for the two fill materials are as shown in \fref{tab:ka}.

\begin{table}[h!tb]
\centering
\begin{tabular}{|l|c|c|c|}
\hline
							& $K_a$			\\ \hline
\textbf{Wall fill material (sand)}		&0.320			\\ \hline
\textbf{Back fill material (clay)}		&0.438			\\ \hline
\end{tabular}
\caption{Active earth pressure coefficients for the fill materials, calculated using \fref{eq:ka}.\label{tab:ka}}
\end{table}







\subsection{Sliding Check\label{sec:sliding}}
For the wall to pass the sliding check, the factor of safety in \fref{eq:factorsliding} must be greater than the chosen value, which is usually a minimum of 2 \citep{WOODS13}.
\begin{equation}
\text{Factor of Safety} = \frac{2 \mu \left( \gamma_w H + w_{s}\right)}{K_{ab}\left( \gamma_{b}H + 2w_{s}\right)\left(\sfrac{H}{L}\right)}
\label{eq:factorsliding}
\end{equation}
\noindent where $H$ is the wall height, $\gamma_w$ is the specific weight of the wall fill, $\gamma_b$ is the specific weight of the backfill, $w_s$ is the surcharge, $K_{ab}$ is the active earth pressure coefficient for the backfill, $L$ is the length of the wall and $\mu$ is the coefficient of friction, and is given by \fref{eq:mu}.

\begin{equation}
\mu = \alpha_s\tan{\phi'_f}
\label{eq:mu}
\end{equation}

\noindent Rearranging \fref{eq:factorsliding} for the length of reinforcement gives:
\begin{displaymath}
L = \frac{\left(FOS\right)K_{ab}\left( \gamma_{b}H + 2w_{sb}\right)H}{2\mu \left( \gamma_w H + w_{sw}\right)}
\end{displaymath}

Choosing a factor of safety of 2 means that the required length of reinforcement to prevent sliding is given by \fref{eq:l_sliding}.
\begin{equation}
L \ge \frac{K_{ab}\left( \gamma_{b}H + 2w_{sb}\right)H}{\mu \left( \gamma_w H + w_{sw}\right)}
\label{eq:l_sliding}
\end{equation}

Therefore, the length of reinforcement required has been calculated as \SI{11.89}{m}. Rounding this to a value that is easy to use on site gives a length of \SI{11.9}{m}.











\subsection{Overturning Check\label{sec:overturning}}
In the overturning check, the factor of safety is the restoring moment divided by the disturbing moment. The overturning moment about the toe is given by \fref{eq:overturning}; the restoring moment is given by \fref{eq:restoring}.

\begin{equation}
M_{overturning} = \left(\frac{K_{ab} \gamma_b H^3}{6}\right) + \left(\frac{K_{ab} w_{sb} H^2}{2}\right)
\label{eq:overturning}
\end{equation}

\begin{equation}
M_{restoring} = \left(\frac{\gamma_w HL^2}{2}\right) + \left(\frac{w_{sw} L^2}{2}\right)
\label{eq:restoring}
\end{equation}


\noindent Thus the factor of safety can be described by \fref{eq:factoroverturning}:

\begin{equation}
\text{Factor of safety} = \frac{3\left(\gamma_w H + w_{sw}\right)}{K_{ab}\left(\gamma_b H + 3w_{sb}\right)\left(\sfrac{H}{L}\right)^2}
\label{eq:factoroverturning}
\end{equation}

Using the same value for the factor of safety as before (FOS = 2), the required length to satisfy the overturning check is given by \fref{eq:l_overturning}:

\begin{equation}
L = H \div \sqrt{\frac{3\left(\gamma_w H + w_{sw}\right)}{K_{ab}\left(\gamma_b H + 3w_{sb}\right)\left(FOS\right)}}
\label{eq:l_overturning}
\end{equation}

Therefore, using \fref{eq:overturning} and \fref{eq:restoring}, the overturning and restoring moments are \SI{1321.5}{kNm m^{-1}} and \SI{11895.2}{kNm m^{-1}} respectively, giving a factor of safety of \si{9} using the design length of \SI{11.9}{m} from the sliding check. The required length of reinforcement to give a factor of safety of 2 is  \SI{5.61}{m}, lower than the required length for the sliding check.








\subsection{Bearing Check\label{sec:bearing}}
Due to the horizontal forces on the back of the wall, the pressure distribution on the underlying soil is not constant (see \fref{fig:pressure} for a sketch).

\begin{figure}[h!tb]
\includegraphics[width=\textwidth]{Bearing_pressures}
\caption{Sketch showing the two components of pressure on the underlying soil: from horizontal forces (top); from vertical forces (bottom) \citep{WOODS13}.\label{fig:pressure}}
\end{figure}

Taking moments about the mid-point of the base, yields \fref{eq:sigmavmax} and \fref{eq:sigmavmin}.


\begin{equation}
\sigma_{Vmax} = \gamma_wH + w_{sw} + K_{ab}\left( \gamma_bH + 3w_{sb}\right)\left(\frac{H}{L_{des}}\right)^2
\label{eq:sigmavmax}
\end{equation}

\begin{equation}
\sigma_{Vmin} = \gamma_wH + w_{sw} - K_{ab}\left( \gamma_bH + 3w_{sb}\right)\left(\frac{H}{L_{des}}\right)^2
\label{eq:sigmavmin}
\end{equation}

\noindent Therefore, using $L_{des} =$ \SI{11.9}{m}, $\sigma_{Vmax} =$ \SI{224.0}{kN m^{-2}} and $\sigma_{Vmin} =$ \SI{112.0}{kN m^{-2}}. As $\sigma_{Vmax}$ is less than the safe bearing pressure $q_{safe}$, and $\sigma_{Vmin} \ge 0$, the design passes the bearing checks.














\FloatBarrier
\subsection{Failure of Geogrid in Tension\label{sec:tension}}
Failure of the geogrid in tension is the main factor in deciding the spacing between layers.

The tension per \si{m} run in any one layer can be calculated by multiplying the vertical stress at that point by the active earth pressure coefficient in the wall. Thus, the tension in layer $i$ can be calculated using:

\begin{equation}
T_i = K_{aw}\sigma_{vi}v_i
\label{eq:ti}
\end{equation}
\noindent Where $\sigma_{vi}$ is the vertical stress on layer $i$ at depth $z_i$, and $v_i$ is the vertical spacing of that layer.

The component of vertical stress arising from the soil's self-weight and the surcharge are given by \fref{eq:swsurcharge}; the vertical stress from the overturning moment on the thrust on the back of the wall can be calculated using \fref{eq:swmoment}. Substituting these two equations into \fref{eq:ti}, setting $T_i = P_d$, and rearranging to find the maximum permissible layer spacing gives \fref{eq:vmax}.

\begin{equation}
\sigma_{vi,weight} = \gamma_wz_i + w_s
\label{eq:swsurcharge}
\end{equation}

\begin{equation}
\sigma_{vi,moment} = K_{ab}\left(\gamma_bz_i + 3w_s\right)\left(\sfrac{z_i}{L}\right)^2
\label{eq:swmoment}
\end{equation}

\begin{equation}
V_{max} = \frac{P_d}{K_{aw}\left[\left(\gamma_w z + w_{sw}\right) + K_{ab}\left(\gamma_b z + 3w_{sb}\right)\left(\sfrac{z}{L_{des}}\right)^{2}\right]}
\label{eq:vmax}
\end{equation}
\noindent Where: $P_d$ is the design strength of the geogrid; $K_{aw}$ and $K_{ab}$ are the active earth pressure coefficients for the wall and the backfill respectively; $\gamma_w$ and $\gamma_b$ are the specific weights of the clay backfill and wall sand; $w_{sw}$ and $w_{sb}$ are the surcharges on the wall and backfill respectively; $z$ is the depth below the top of the wall and $L_{des}$ is the design length of geogrid reinforcement.


The design brief dictates that the minimum thickness of a reinforcement layer is \SI{150}{mm}. Therefore the maximum spacing between layers ($V_{max}$) has been calculated using \fref{eq:vmax} at vertical intervals of \SI{0.15}{m} for both geogrid grades to facilitate selection:


\begin{longtable}{|p{.2\textwidth}|p{.2\textwidth}|p{.2\textwidth}|}
\hline
				&\multicolumn{2}{c|}{$\mathbf{V_{max}}$ (\si{mm})} 	\\ \hline
\textbf{z} (\si{m})	 	&\textbf{RE55}			&\textbf{RE80}				\endhead \hline
0.00	&1570	&2350\\ \hline
0.15	&1433	&2145\\ \hline
0.30	&1318	&1972\\ \hline
0.45	&1218	&1824\\ \hline
0.60	&1132	&1695\\ \hline
0.75	&1057	&1582\\ \hline
0.90	&990	&1482\\ \hline
1.05	&931	&1393\\ \hline
1.20	&877	&1313\\ \hline
1.35	&829	&1241\\ \hline
1.50	&786	&1176\\ \hline
1.65	&746	&1117\\ \hline
1.80	&710	&1063\\ \hline
1.95	&677	&1013\\ \hline
2.10	&646	&967\\ \hline
2.25	&618	&925\\ \hline
2.40	&592	&886\\ \hline
2.55	&567	&849\\ \hline
2.70	&544	&815\\ \hline
2.85	&523	&783\\ \hline
3.00	&503	&753\\ \hline
3.15	&484	&725\\ \hline
3.30	&467	&699\\ \hline
3.45	&450	&674\\ \hline
3.60	&434	&650\\ \hline
3.75	&420	&628\\ \hline
3.90	&406	&607\\ \hline
4.05	&392	&587\\ \hline
4.20	&380	&568\\ \hline
4.35	&367	&550\\ \hline
4.50	&356	&533\\ \hline
4.65	&345	&516\\ \hline
4.80	&335	&501\\ \hline
4.95	&325	&486\\ \hline
5.10	&315	&472\\ \hline
5.25	&306	&458\\ \hline
5.40	&297	&445\\ \hline
5.55	&289	&432\\ \hline
5.70	&281	&420\\ \hline
5.85	&273	&409\\ \hline
6.00	&266	&398\\ \hline
6.15	&259	&387\\ \hline
6.30	&252	&377\\ \hline
6.45	&245	&367\\ \hline
6.60	&239	&357\\ \hline
6.75	&233	&348\\ \hline
6.90	&227	&339\\ \hline
7.05	&221	&331\\ \hline
7.20	&215	&322\\ \hline
7.35	&210	&315\\ \hline
7.50	&205	&307\\ \hline
\caption{Maximum permissible vertical spacing $V_{max}$ between geogrid layers at depth $z$ for each grade of reinforcement.\label{tab:vmax}}
\end{longtable}

\FloatBarrier
\subsubsection{Spacing Option using RE55 Geogrids}
\begin{figure}[h!tb]
\centering
\includegraphics[width=.8\textwidth]{Spacing_selection_55}
\caption{Choice of layers \& spacing using only RE55 grade geogrids; layer locations are shown along the y-axis.\label{fig:spacing_RE55}}
\end{figure}

The RE55 grade geogrids are weaker but cheaper than the RE80 grade \citep{TENSAR10}. The best spacing option using RE55 grade geogrids is represented graphically in \fref{fig:spacing_RE55} and in tabular form in \fref{tab:re55}. Although these geogrids are cheaper per unit area than the heavier grade, this may not be the cheapest solution because it could be possible to have fewer, stronger grids at greater spacings - although the grids would cost more per unit area, the total cost may be lower. This solution is also not ideal because it contains so many geogrids in the lower layers, and will therefore take a long time to construct.



\begin{longtable}{|p{.15\textwidth}|p{.30\textwidth}|p{.2\textwidth}|}
\hline
\textbf{Depth} (\si{m})	&\textbf{Layer thickness} (\si{mm})	&\textbf{Geogrid type}\endhead \hline
0.90	&900	&RE55\\ \hline
1.50	&600	&RE55\\ \hline
2.10	&600	&RE55\\ \hline
2.55	&450	&RE55\\ \hline
3.00	&450	&RE55\\ \hline
3.30	&300	&RE55\\ \hline
3.60	&300	&RE55\\ \hline
3.90	&300	&RE55\\ \hline
4.20	&300	&RE55\\ \hline
4.50	&300	&RE55\\ \hline
4.80	&300	&RE55\\ \hline
5.10	&300	&RE55\\ \hline
5.25	&150	&RE55\\ \hline
5.40	&150	&RE55\\ \hline
5.55	&150	&RE55\\ \hline
5.70	&150	&RE55\\ \hline
5.85	&150	&RE55\\ \hline
6.00	&150	&RE55\\ \hline
6.15	&150	&RE55\\ \hline
6.30	&150	&RE55\\ \hline
6.45	&150	&RE55\\ \hline
6.60	&150	&RE55\\ \hline
6.75	&150	&RE55\\ \hline
6.90	&150	&RE55\\ \hline
7.05	&150	&RE55\\ \hline
7.20	&150	&RE55\\ \hline
7.35	&150	&RE55\\ \hline
7.50	&150	&RE55\\ \hline
\caption{Spacing option using RE55 grade geogrids only.\label{tab:re55}}
\end{longtable}










\FloatBarrier
\subsubsection{Spacing Option using RE80 Geogrids}
The RE80 grade geogrids are weaker but cheaper than the RE55 grade \citep{TENSAR10}. The best spacing option using RE80 grade geogrids is represented graphically in \fref{fig:spacing_RE80}\footnote{This figure shows a spacing greater than 1m. I realise this is not recommended, but do not have time to change it. My final solution has a maximum spacing of \SI{900}{mm}.} and in tabular form in \fref{tab:re80}. This option has far fewer geogrids than the option using RE80 grids only, mainly due to the fact that it can be placed in \SI{300}{mm} layers in the lower regions rather than the \SI{150}{mm} layers required for the RE55's. Although this should make construction faster, the stronger geogrids may be wasted in the upper layers.

\begin{figure}[h!tb]
\centering
\includegraphics[width=.8\textwidth]{Spacing_selection_80}
\caption{Choice of layers \& spacing using only RE80 grade geogrids; layer locations are shown along the y-axis.\label{fig:spacing_RE80}}
\end{figure}

\begin{table}[h!tb]
\centering
\begin{tabular}{|p{.15\textwidth}|p{.30\textwidth}|p{.2\textwidth}|}
\hline
\textbf{Depth} (\si{m})	&\textbf{Layer thickness} (\si{mm})	&\textbf{Geogrid type}\\ \hline
1.20	&1200	&RE80\\ \hline
2.10	&900	&RE80\\ \hline
2.70	&600	&RE80\\ \hline
3.30	&600	&RE80\\ \hline
3.90	&600	&RE80\\ \hline
4.35	&450	&RE80\\ \hline
4.80	&450	&RE80\\ \hline
5.10	&300	&RE80\\ \hline
5.40	&300	&RE80\\ \hline
5.70	&300	&RE80\\ \hline
6.00	&300	&RE80\\ \hline
6.30	&300	&RE80\\ \hline
6.60	&300	&RE80\\ \hline
6.90	&300	&RE80\\ \hline
7.20	&300	&RE80\\ \hline
7.50	&300	&RE80\\ \hline
\end{tabular}
\caption{Spacing option using RE80 grade geogrids only.\label{tab:re80}}
\end{table}









\FloatBarrier
\subsubsection{Final solution: Spacing Option using both RE55 and RE80 Geogrids}

Previously, options using only one grade of geogrid have been considered. However, it is possible to use a mix of the two grades to gain the benefits of both. The solution represented in \fref{fig:spacing_RE55_RE80} and \fref{tab:re55_re80} makes use of the ability of the stronger RE80 grid to be placed with greater spacing near the base of the wall, whilst using the lower strength grid in the upper part of the wall where the horizontal stress is lower. This is the option that will be carried forwards to the pull-out checks. The relative merits of this option with respect to construction and safety are discussed further in \fref{sec:appraisal}.



\begin{figure}[h!tb]
\centering
\includegraphics[width=.9\textwidth]{Spacing_selection_55_80_1}
\caption{Choice of layers \& spacing using both RE55 and RE80 grade geogrids; layer locations and types are shown along the y-axis.\label{fig:spacing_RE55_RE80}}
\end{figure}

\begin{table}[h!tb]
\centering
\begin{tabular}{|p{.15\textwidth}|p{.30\textwidth}|p{.2\textwidth}|}
\hline
\textbf{Depth} (\si{m})	&\textbf{Layer thickness} (\si{mm})	&\textbf{Geogrid type}\\ \hline
0.9	&900	&RE55\\ \hline
1.5	&600	&RE55\\ \hline
2.1	&600	&RE55\\ \hline
2.6	&450	&RE55\\ \hline
3.0	&450	&RE55\\ \hline
3.3	&300	&RE55\\ \hline
3.6	&300	&RE55\\ \hline
3.9	&300	&RE55\\ \hline
4.2	&300	&RE55\\ \hline
4.5	&300	&RE55\\ \hline
4.8	&300	&RE55\\ \hline
5.1	&300	&RE55\\ \hline \hline
5.4	&300	&RE80\\ \hline
5.7	&300	&RE80\\ \hline
6.0	&300	&RE80\\ \hline
6.3	&300	&RE80\\ \hline
6.6	&300	&RE80\\ \hline
6.9	&300	&RE80\\ \hline
7.2	&300	&RE80\\ \hline
7.5	&300	&RE80\\ \hline
\end{tabular}
\caption{Spacing option using both RE55 and RE80 grade geogrids.\label{tab:re55_re80}}
\end{table}













\newpage
\FloatBarrier
\subsection{Wedge Pullout Failure\label{sec:wedge}}
Having already ensured that no single layer of geogrid will fail in tension, the possibility of the geogrid layers experiencing a loss of bond with the surrounding soil and pulling out will now be considered.

As per the design brief, two wedge pullout failure mechanisms have been checked: one with the bottom of the wedge at half of the wall height (i.e.  $z = \sfrac{H}{2}$, only the geogrid layers in the top half of the wall must be pulled out), and the second with the bottom of the wedge at the base of the wall (i.e. $z = H$, all of the geogrid layers must be pulled out).
\\
\\
\noindent The following calculations are based on two assumptions:
\begin{itemize}
\item The wedge behaves as a rigid body.
\item Friction between the facing and the fill can be ignored.
\end{itemize}




\subsubsection{Mobilising Force}
\noindent The forces on a trial wedge are depicted in \fref{fig:wedge}, where $F_L$ and $S_L$ are the horizontal and vertical thrust from an abutment respectively. Therefore, the total force that must be carried by the reinforcement layers to prevent failure is given by \fref{eq:t}.

\begin{figure}[h!tb]
\centering
\includegraphics[width=.5\textwidth]{Trial_wedge}
\caption{Forces acting on a trial wedge \citep{WOODS13}.\label{fig:wedge}}
\end{figure}

\begin{equation}
T = \left(\frac{h\tan{\beta}\left(\gamma_wh + 2w_s\right) + 2S_L}{2\tan{\left(\phi'_w + \beta\right)}}\right) + F_L
\label{eq:t}
\end{equation}

Since there is no abutment included in the design, $S_L = 0$ and $F_L = 0$, \fref{eq:t} becomes \fref{eq:tsimple}, and the maximum value of $T$ will occur when $\beta = \ang{45} - \sfrac{\phi'_w}{2}$.

\begin{equation}
T = \frac{h\tan{\beta}\left(\gamma_wh + 2w_s\right)}{2\tan{\left(\phi'_w + \beta\right)}}
\label{eq:tsimple}
\end{equation}

\noindent The mobilising forces are therefore \SI{236.8}{kN m^{-1}} for the full height wedge, and \SI{76.8}{kN m^{-1}} for the half height wedge.

\subsubsection{Resisting Force}
The maximum pull-out resistance of each geogrid layer was then calculated to check that each wedge had sufficient total capacity to resist the mobilising force. 

A factor of safety of 2 was used along with \fref{eq:lai} and \fref{eq:tai} to calculate the anchorage length and pull-out forces. The results for wedge 1 (full height) are displayed in \fref{tab:tai_w1}; the results for wedge 2 (top half) are displayed in \fref{tab:tai_w2}.


\begin{equation}
L_{ai} = L_{des} - \left(h - z\right) \tan{\left(\beta\right)}
\label{eq:lai}
\end{equation}


\begin{equation}
T_{ai} = \frac{2 L_{ai} \alpha_p\tan{\left(\phi'\right)}\sigma'_v}{FOS}
\label{eq:tai}
\end{equation}

\begin{table}[h!tb]
\centering
\begin{tabular}{|c|c|c||c|c|}
\hline
\textbf{z} (\si{m})	&$\mathbf{L_{ai}}$ (\si{m})	&$\mathbf{T_{ai}}$ (\si{kN m^{-1}})	&\textbf{Type}	&$\mathbf{P_d}$ (\si{kN m^{-1}})\\ \hline
0.90	&8.17	&202.7	&RE55	&14.7\\ \hline
1.50	&8.51	&262.2	&RE55	&14.7\\ \hline
2.10	&8.84	&325.7	&RE55	&14.7\\ \hline
2.55	&9.10	&376.1	&RE55	&14.7\\ \hline
3.00	&9.35	&428.7	&RE55	&14.7\\ \hline
3.30	&9.52	&465.1	&RE55	&14.7\\ \hline
3.60	&9.69	&502.4	&RE55	&14.7\\ \hline
3.90	&9.86	&540.8	&RE55	&14.7\\ \hline
4.20	&10.03	&580.3	&RE55	&14.7\\ \hline
4.50	&10.20	&620.7	&RE55	&14.7\\ \hline
4.80	&10.37	&662.2	&RE55	&14.7\\ \hline
5.10	&10.54	&704.6	&RE55	&14.7\\ \hline
5.40	&10.71	&748.1	&RE80	&22.0\\ \hline
5.70	&10.88	&792.6	&RE80	&22.0\\ \hline
6.00	&11.05	&838.2	&RE80	&22.0\\ \hline
6.30	&11.22	&884.7	&RE80	&22.0\\ \hline
6.60	&11.39	&932.3	&RE80	&22.0\\ \hline
6.90	&11.56	&980.9	&RE80	&22.0\\ \hline
7.20	&11.73	&1030.5	&RE80	&22.0\\ \hline
\multicolumn{2}{|r|}{Totals}&\textbf{11878.8}&	&\textbf{330.4}\\ \hline
\end{tabular}
\caption{Anchorage length, pull-out forces, and grid strength for wedge 1 (full height).\label{tab:tai_w1}}
\end{table}

\begin{table}[h!tb]
\centering
\begin{tabular}{|c|c|c||c|c|}
\hline
\textbf{z} (\si{m})	&$\mathbf{L_{ai}}$ (\si{m})	&$\mathbf{T_{ai}}$ (\si{kN m^{-1}})	&\textbf{Type}	&$\mathbf{P_d}$ (\si{kN m^{-1}})\\ \hline
0.90	&10.29	&255.4	&RE55	&14.7\\ \hline
1.50	&10.63	&327.6	&RE55	&14.7\\ \hline
2.10	&10.97	&403.9	&RE55	&14.7\\ \hline
2.55	&11.22	&463.8	&RE55	&14.7\\ \hline
3.00	&11.48	&525.9	&RE55	&14.7\\ \hline
3.30	&11.65	&568.7	&RE55	&14.7\\ \hline
3.60	&11.82	&612.4	&RE55	&14.7\\ \hline
\multicolumn{2}{|r|}{Totals}&\textbf{3157.6}&	&\textbf{102.9}\\ \hline
\end{tabular}
\caption{Anchorage length, pull-out forces, and grid strength for wedge 2 (half height).\label{tab:tai_w2}}
\end{table}

\noindent As can be seen in \fref{tab:tai_w1}, and \fref{tab:tai_w2}, the total available pull-out resistance for both wedges is far greater than the mobilising force. However, where the pull-out force $T_{ai}$ is greater than the installed strength of the geogrid $P_d$, $P_d$ governs the resisting force. $P_d$ for RE55 and RE80 grids is \SI{14.7}{kN m^{-1}} and \SI{22.0}{kN m^{-1}} respectively. Therefore, since the pull-out force $T_{ai}$ is greater than $P_d$ in all layers for both grid types, the total resisting forces are \SI{330.4}{kN m^{-1}} and \SI{102.9}{kN m^{-1}} for the large and small wedges respectively. Since the available resistance is greater than the mobilising force for both cases, both wedges pass the check.











\section{Expected Construction Sequence}
The brief states that the construction is a ``motorway \emph{embankment}'', as opposed to a motorway \emph{cutting}. Therefore, it will be assumed that ground level prior to construction is constant across the site (at a level marked ``\SI{0}{m}'' on \fref{fig:section}) and that the new carriageway is to be at the level marked ``\SI{10}{m}'' in the same figure. It is also assumed that the precast concrete facing panels are modular, will lock in to the units below them and have sufficient strength to retain the soil at the front face during compaction. A brief summary of the expected construction sequence is as follows:
\begin{enumerate}
\item Strip \SI{500}{mm} of soil away from the ground surface to remove weathered material.
\item Excavate a hole for, and place, the toe piece.
\item Erect some kind of temporary support or formwork at what is to be the back of the wall. This is required to prevent loss of soil during layer placement \& compaction, and could be:
\begin{itemize}
\item Wooden formwork.
\item Temporary sheet piling.
\item Temporary propped retaining wall.
\item Any other suitable support.
\end{itemize}
\item Place the bottom layer geogrid.
\item Install the first (bottom) precast concrete face unit.
\item Place and compact \SI{150}{mm} of sand using a ``whacker plate''. Repeat until the next layer with a geogrid.
\item Wrap both ends of the bottom layer of geogrid around and over the compacted layer(s). Place the next layer of geogrid, then repeat step 6 until the next geogrid is required. Install facing units as necessary.
\item Install the last geogrid and place \& compact the layers of soil above it.
\item As both ends of the geogrid have been wrapped around the compacted layers of soil, the back of the wall should now be able to support its own weight. Remove the temporary support and backfill with clay.
\end{enumerate}





\newpage
\section{Design Appraisal \label{sec:appraisal}}
\subsection{Sustainability}
Recycled materials should be used wherever possible. In particular for this design, fill materials could be from recycled sources provided they have the necessary mechanical properties ($\phi'$, $c'$, $\gamma$ etc.). Where recycled materials are unsuitable, local sources of material should be considered to reduce transport emissions.

Although the geogrids themselves are made from polymer, and their manufacture contributes to global $CO_2$ emissions, their use is saving a large volume of fill material that would constitute the lower slope in an unreinforced design. Consequently, geogrid use in the design may lead to a more sustainable solution when the cost of transporting fill material is included.


\subsection{Health \& Safety}
This section deals with health and safety aspects most relevant to the construction stage.
\begin{itemize}
\item Geogrid material is heavy and is not to be lifted without mechanical aid if the roll weighs over \SI{20}{kg}.
\item The geogrids used in the design are made from polymer, and are therefore vulnerable to UV degradation. They should be stored out of direct sunlight, and once placed should be covered with soil as soon as possible.
\item Care should be taken when using plant (whacker plates etc.) close to the edge of the wall to avoid the risk of collapse.
\item The geogrid cutting should be undertaken with care, using gloves to minimise the chance of injury.
\item During the wall's construction, especially in the later stages, the labourers will be working at heights of up to \SI{7}{m}. There should be adequate fall restraints in place to prevent falls when working close to the edge, and labourers should keep away from the edge wherever possible.
\item Because the labourers may be walking on the geogrid, there is a significant risk of injury from slips and trips. The workspace should be kept as clear as possible, and care should be taken when moving around the site at all times to minimise this risk.
\item Care should be taken not to damage the geogrid when installing it.
\item Compacted materials should be inspected by a competent person.
\end{itemize}

\subsection{CDM Regulations}
The Construction, Design and Management regulations (2007) require designers to consider health and safety aspects during the design process, in able to design something that can be constructed safely. This section deals with health and safety aspects most relevant to the design.
\begin{itemize}
\item By keeping the locations of the geogrids at multiples of \SI{150}{mm} depths, construction has been simplified and the possibility of placing a grid in the wrong location has been reduced.
\item It must be noted that there is a possibility of using the wrong type of geogrid in the wrong layer, which could potentially lead to failure. Although the grids are colour coded, as can be seen in \fref{fig:Geogrid_properties}, the construction drawings should make note of this residual risk and clearly mark the location of the changeover from RE55 to RE80 grids. The slightly increased risk of using two different types of grid can be justified by the cost benefit, and should not be a problem if construction is overseen by a competent engineer.
\item At present, the quality of the site investigation is unknown. If possible, further steps should be taken to check the underlying soil for voids or other hazards that could cause the structure to fail (e.g. a void under the bottom layer of geogrid could place the material under extra tensile load, leading to failure).
\item As there is to be a highway on top of the embankment, it is probable that a crash barrier of some kind will be required to protect motorists from the \SI{10}{m} drop. The additional horizontal load that this would apply to the structure in the event of a collision has not been considered.
\item The effects of post-construction damage to the structure have also not been considered.
\end{itemize}

It is also important to realise that the geogrid long term strength is a \emph{prediction} - a theoretical value that has not been directly measured, which is based on observations during long-term creep strain and rupture testing:
\begin{quote}
``Using principles of time/temperature superposition, predicted long-term strengths for a design life of 120 years and a design temperature of 10°C or 20°C have been obtained from the measured data without the need for direct extrapolation.'' \citep{TENSAR10}
\end{quote}
Although the values can be used with a reasonable degree of certainty, there is some residual risk involved.



%\nocite{*}
\printbibliography

\end{document}

WARNING: don't actually read it unless you're having trouble sleeping

Feathers

[richb]

Couple of weeks! I think that for casual users it is not worth the effort. A simple presentation can be created in one of the suite apps without much study or effort. For professional presentations and scholarly presentations you are probably right.

[Feathers McGraw]

Sorry, that was a bit misleading. Half an hour to produce a document, by the end of a fortnight I was pretty good!

[SteveRiley]

I ....would......have put the .pdfs into a .zip file but.........I found out that MOST people in a windoze centric world have NO CLUE about how to open a zip file...

Windows Explorer has transparently handled ZIP files (as compressed folders) since XP. No third party tools are necessary.

does MS work with many apple products....um no..

Microsoft Office for Mac is, last time I checked, the number one selling Mac software product. iTunes for Windows probably has more users than Windows Media Player.

[richb]

Sorry, that was a bit misleading. Half an hour to produce a document, by the end of a fortnight I was pretty good!

What's a fortnight? A night in a fort.

[Feathers McGraw]

What's a fortnight? A night in a fort.

Um... lol?!

[SteveRiley]

What I wanna know is... what's the speed of light in furlongs per fortnight?

[andystmartin]

furlong/fortnight is approximately 6012.8848 * meters/sec.

So, c is approximately 1,802,600,000,000 furlongs/sec (1.8026E12)

[The "units" program in Linux can do some amazing things.]

[SteveRiley]

Yay! I propose that we adopt the FFF System (furlong/furkin/fortnight) for all official KFN measurement reporting.

[Feathers McGraw]

Yay! I propose that we adopt the FFF System (furlong/furkin/fortnight) for all official KFN measurement reporting.

Did you just write that Wikipedia page? I wouldn't put it past you, not in a hundred blue moons.

[oshunluvr]

I, for one, can't believe that I just wasted like 80 microfortnights to read this thread...