Transport and Road Research Laboratory
Crowthorne Berkshire United Kingdom
A users manual for a program to analyse
y namic cone penetrometer data Overseas Road Note 8
Department of Transport
Overseas Development Administration Transport and Road Research Laboratory Overseas Unit ACKNOWLEDGEMENTS
The work described in this report was carried out in the
Overseas Unit of the TRRL. The report is based on a
text prepared by Howard Humphreys and Partners,
Consulting Engineers. The computer program itself is
based on an original mainframe program written by
Neil Howitt and Dr. J. Rolt and modified by Trevor
Bell of Contract Data Research Ltd. for use on
First published 1990
OVERSEAS ROAD NOTES
Overseas Road Notes are prepared principally for road
and road transport authorities in countries receiving
technical assistance from the British Government. A
limited number of copies is available to other
organisations and to individuals with an interest in
roads overseas, and may be obtained from:
Transport and Road Research Laboratory
Crowthorne, Berkshire, RG11 6AU England
© Crown copyright 1990 Limited extracts from the
text may be produced provided the source is
acknowledged. For more extensive reproduction,
please write to Head of Overseas Unit, Transport
and Road Research Laboratory CONTENTS
INDEMNITY NOTE 1
1. INSTALLATION INSTRUCTIONS 2
2. PROGRAM OPERATION 3
2.1 Starting the Program 3
2.2 TRRL DCP Option List 3
2.3 How to Enter Data 3
2.4 Amend/Review Data 4
2.5 Do not... 4
2.6 What to do in the Event of a Computer Failure 4
2.7 Always... 4
2.8 Command Line 4
2.9 OK? Prompt 5
2.10 Recall File 5
2.11 Save File 5
2.12 Data Filenames 5
3. PROCESSING DCP DATA 6
3.1 Introduction 6
3.2 The NEW Command 6
3.3 The RECALL Command 7
3.4 The EDIT Command 7
3.5 The INSERT Command 8
3.6 The DELETE Command 8
3.7 The KILL Command 8
3.8 The SAVE Command 8
3.9 The MORE Command 8
3.10 The OPTIONS Toggle Command 8
3.11 The ANALYSE Command 8
3.12 The VIEW Command 9
3.12.1 I/O: Zoom Functions 11
3.12.2 S/D/E/X: Panning Functions 11
3.12.3 G: Grid Toggle 11
3.12.4 V: View Point 11
3.12.5 P: Print or Plot 12
3.12.6 Esc: End Graphics 12
3.13 The PRINT Command 12
3.14 The FILE Command 12
3.15 The TOL Command 12
3.16 The Structural Number (SN) Command 13
4 FILE MAINTENANCE 14
4.1 Introduction 14
4.2 Assign Data Drive 14
4.3 Paper Length/Beeper Control 14
4.4 Enter Printer Controls 15
4.5 Assign Graphic Devices 15
4.6 Test Graphics Screen 16
4.7 Test Graphics Printer 16
4.8 Specify Graphics Parameters 16
4.9 Batch Print 16
4.10 CBR Relationships 17 INDEMNITY NOTE
Note must be taken by all users of this program
that TRRL DCP is not intended to replace normal
engineering judgement. The procedures described
in this manual are intended for users who already
have a thorough understanding of DCP analysis
and are capable of deciding which method of
analysis is most appropriate for individual
situations. The user must be aware of the
limitations of the program and, most importantly,
that incorrect data input must lead to incorrect
data output. The user should be capable of
assessing the accuracy of any results produced. No
warranty can be given on the validity of the results
and the ultimate responsibility for acceptance and
subsequent use of any results lies solely with the
TRRL DCP is the copyright of:
The Overseas Unit of the
Transport and Road Research Laboratory
United Kingdom INTRODUCTION
TRRL DCP is a program designed to help with
the interpretation and presentation of DCP test
TRRL DCP has been written to operate under
MSDOS and PCDOS compatible microcomputer
operating systems. The program is totally
interactive with `Help' facilities, and is highly user-
friendly with rigorous error checking at data input.
Throughout this manual, whenever the user is
required to enter text in response to prompts from
the program, the text is denoted thus: [TEXT].
Input commands in the form of single keystrokes
are denoted: .
1 1. INSTALLATION
The TRRL DCP analysis software is contained on
an installation floppy disc which MUST be
installed on the host computer before it will
operate. (i.e. the software will not work from the
There are three stages of installation. Firstly the
relevant files are copied automatically from the
installation disc to the host computer's hard disc,
then the type of computer display and graphics
standard is specified and finally the data disc
drive, printer controls, test graphics, etc are
The three stages are carried out as follows. (It is
assumed that the floppy disc is in drive A and the
hard disc is drive C. The appropriate characters
must be substituted for A and C if other disc
configurations are used.)
Insert the floppy disc in drive A and type:
A: [INSTALL A C] . This instruction
causes the required files to be copied from
drive A to a new sub directory named DCP on
drive C. On completion, remove the floppy
disc and store safely.
The computer graphics screen must be either
CGA, MDA, EGA or HERC and will be either
MONO or COLOUR. To install the graphics
system type the following sequence: e.g. for a
[DCPINST HERC MONO]
An unacceptable combination of graphics and
screen type will result in an error message.
Start the program by typing [DCP] . Press any key to clear the first
display and choose Option 2 (File
Maintenance) from the main option list. A new
option list will appear.
Select Option 1 to specify the data drive (i.e.
where data files will be stored). Option 2 to set
Options 3 and 4 should already have been
preset and need not be changed.
Options 5 and 6 should be used to test the
graphics screen and to test graphics on the
2printer. In both cases a standard `test card'
By aping back through the options the user
will leave the program. The software will now be
fully installed and may be used at any time by typing
[DCP] . A data file named TEST is
available on disc and may be used to demonstrate the
scope of the software. This file is referred to
throughout the manual.
Once the program has been successfully installed a
back-up copy should be made and stored safely. 2. PROGRAM OPERATION
2.1 Starting the Program
The computer should be started in the normal
way. TRRL DCP will be in a sub-directory of the
hard disc. To start the program change to the sub-
directory, and type [DCP] . After
loading the necessary graphics devices the
computer will display the following notice to the
Pressing a key at this point gives access to the
main option list.
2.2 TRRL DCP Option List
The user may move around the option list by using
the left or right arrow keys until the required option
is highlighted with an asterisk. This optionis also shown towards the bottom left-hand corner
of the screen and will be selected if the key is pressed. Alternatively the user
may press the number shown in front of the
On completion of any option, the user is returned
to this main option list.
If the ape key is pressed, the user is
offered the opportunity to end and to return to
the computer's operating system.
2.3 How to Enter Data
The programs operate in an `interactive' style.
Questions or requests for information are displayed
within `fields' on the computer screen and
responses from the operator are made through the
computer keyboard. Every time an item of
information has been entered through the keyboard,
the key must be pressed for the
computer to accept the data, if the data field
(spaces between square brackets) has not been
entirely occupied. However, if the response totally
fills the data field the computer automatically
accepts the data. For computers with a reverse
video facility, the data field and square brackets are
shown in reverse video. The computer will wait
indefinitely until a response is entered to a request
and, subject to the conditions above, the key is pressed.
The program displays a series of `pages' on the
computer screen. The name of the program
appears in the top left corner. At the bottom left-
hand side of the screen is an `error' line for the
display of error messages, while in the bottom
right-hand corner of the screen the user is shown
which key (usually ape) to press to end a
particular operation and proceed to the next
logical step in the program.
The ape key may be used at most points in
the program to leave certain pages, either when
data entry is completed or the user wishes to abort.
Also shown at the bottom right hand corner is the
`Help' key. On most computers the and
[?] must be pressed simultaneously.
If help is selected a message will be displayed at
the top of the screen which will give further
3 4information or instructions on how to proceed
with the program. A typical example is:
The program incorporates an error-checking
system to ensure that the data entered is logical
and consistent in relation to the data requested. At
the bottom of the screen is an error line which
will display error messages in the event of invalid
data being entered.
For example, if a number is being requested and
an alphabetic character is entered in error, an
`Invalid Data' message will appear as follows and
the correct data must be re-entered.
The invalid data message may appear for many
reasons and will usually be obvious. However, the
`Help' system may give some indication of why
data is not accepted.
2.4 Amend/Review Data
At any stage of entering or amending the data a
simple editing facility is available. This involves the
use of two keys which are pressed simultaneously to
perform each function, one of which is the control key. + [X] move down to next batch of fields + [E] move back to last field + [D] move right on command lineOn most computers, these commands are available
using the arrow keys on the keyboard. The simplest
way to erase data in a complete cell is to enter a
space followed by a . On reviewing
data a skips to the next data field.
2.5 Do Not...
The program is equipped with thorough error
checking routines but there are still a number of
operations that the user may carry out which would
have disastrous consequences but which cannot be
overruled by the program.
RESET or BOOT the computer while the
program is in operation. This will re-set the whole
system with the loss of data.
open the disc drive doors and remove or
replace discs unless specifically instructed by the
computer. This may result in a system failure and
the loss of data.
press the and [C] keys
simultaneously while the program is in operation.
This may stop the program and cause the loss of
turn the computer off until instructed to do
2.6 What to do in the Event of a
If for any reason, there is a failure, it will be fairly
obvious which data has and has not been recorded
successfully. If there is any doubt, the back-up
copies of the data should be used to start the data
input session again.
2.7 Always . . .
There is one cardinal rule for any computerised
system. ALWAYS make back-up copies of all
current data after entering ANY new information.
The copying procedure will vary between the
different types of computer and reference should be
made to the Operating System manual and Section
2.12 for details of relevant filenames.
2.8 Command Line
Throughout the program the user is presented with
a command line near the bottom of the screen
thus: If your screen supports reverse video, the current
option will be shown in reverse video, and will
appear to the right of the word `Command'. To
select options, the user may press the space bar or
the left and right cursor keys, until the desired
option has been highlighted. To enter the option
the user presses the key. The user
may also jump to an option by entering the first
letter of the required option. To exit from the
command line the user must press the ape
2.9 OK? Prompt
Throughout the program the user will be asked to
confirm that the displayed data is OK with the
following message at the bottom of the screen.
The user has three possible responses to this
Enter [Y] for yes and continue
Enter [N] for no, go back and review
Enter ape for no and quit this operation.
2.10 Recall File
The user may recall data files previously saved on
disc by moving the cursor to the RECALL command
and pressing .
Use of this option will clear any data in memory and
load the recalled data. The user has only to enter the
filename. Sub-directories, data drives or file
extensions must not be specified. Alternatively, the
user may enter [DIR] to obtain a list of those files
which may be recalled.
2.11 Save File
The user may save data files on disc by moving the
cursor to the SAVE command and pressing .
Use of this option will save the data currently
displayed to the specified file. If the specified file
already exists it will be overwritten. Note that it is
only necessary to enter the filename and that file
extensions, data drives and sub-directories are notrequired. A list of files already saved on disc can
be displayed by typing [DIR].
2.12 Data Filenames
Throughout the program, data files are created and
stored on the data disc. [FILENAME] is a
user-specified filename of up to 8 characters. A
three character filename extension, [FILENAME].
DCP, is automatically given to each data file. The
user is not required to enter the drive specification
nor the filename extension in response to filename
When batch printing a file, a new file is
automatically created with the same filename as
the data filename but with the file extension .FIL.
(See Section 4.9).
5 Site: Description of the site [20
Section no. Details of the section no. [20
Text: Details of the test no: [20
Chainage: Details of the chainage [20
Direction/lane Details of the direction and
lane [20 characters]
Position/offset Details of the position of
offset [20 characters]
Date: Date of the test [20
Start layer: Description of the surface or
upper layer [20 characters]
Condition: Condition of the start layer
Zero error (mm): If, for various reasons while
conducting the DCP test, the
reading is not zero at zero
blows the reading should be
Surf thick (mm): Enter the thickness of the
surface layer in millimetres.
This layer will generally be a
very hard layer through
which a hole has been
chiselled or drilled.
Extens @ line- Here the user should enter
the line number at which any
extension rod was added to
the DCP apparatus. At this
point the scale reading will
have been recalibrated and
the user will have entered
two readings for the same
number of blows. In the
example below an extension
rod of 400 mm was added
after 169 blows when the
reading was 466 mm. The
new scale reading is 66 mm
after which the data entry
can continue as normal.
3. PROCESSING DCP DATA
This option allows the entry of new data as well as
the editing and storage of existing data. Data
printouts and plots of the DCP curves may also be
obtained in this option.
On selecting the 'Process DCP Data' option, the
following screen is displayed:
Along the bottom of the screen a menu is
displayed and these options are explained in turn
3.2 The NEW Command
The NEW command is used to clear all existing
data and start the entry of new data. If data
already exists, the user is required to confirm that
this data is to be cleared from memory as follows:
If data is not to be lost irretrievably it should first
be saved using the 'save' command as detailed in
If the user enters [Y] to the 'Current data saved
OK?' prompt then the data currently displayed will
be cleared both from the screen and from the
memory, and the cursor will move to the first field
in the table ready for the input of new data. Once the data has been entered the user should ape in the normal way, see section 2.3 and a
recalculation message will be displayed. After the
program has made provision for any extension rods
the above data input will appear as follows. The user
is required to enter yes [Y] to confirm that the
recalculation is satisfactor
Blows/Rdng:Enter the number of blows in
the left hand column and the
corresponding reading or
depth of the DCP probe in the
column to the right. Once all
the required data fields have
been entered, (100 max) ape from the New
The data in each file is split into 3 sections called:
(i) Descriptive data: As the name suggests
this data describes the site and
conditions and is found on the top half
of the screen.
(ii) Test data page 1: These are the blows
and corresponding readings for the first
50 data records
(iii) Test data page 2: These are the blows and
corresponding readings for the second 50
During data input the screen will move
automatically to page 2 after page 1 has been
filled with data. In order to move back to view
page 1 again, it is necessary to save the file (see
section 2.11) after which it is possible to select the
edit facility (see section 3.4) and make any
3.3 The RECALL Command
The RECALL command is used to recall and
display a previously saved data file, see Section
2.11. This data file will replace any data already
displayed. The user is required either to enter the
filename or to enter [DIR] to produce a list of all
existing filenames. If a filename has already been
specified for the data shown, its name will be
displayed in the data box. If the key
is pressed, the filename will default to the display
After the data has been recalled from disc it is
displayed. Any errors will be displayed as an error
message to remind the user of invalid data. The
name of the current DCP data file will be
displayed in the top right hand corner of the
screen, as follows:
The DCP data may then be edited, viewed,
printed etc. If the user tries to recall a file
which does not exist an error message will
appear `File not found'.
3.4 The EDIT Command
The EDIT command is used to edit data in an
existing data file. The cursor moves to the site cell
and may be moved from cell to cell or field to field
either by entering modified data or by
7 pressing the key. If the only data to
be modified is further down the file then the down
arrow key may be pressed to move down until the
line to be changed is reached. The ape key
may be pressed to end an edit of the particular
page as explained in section 3.2. To move back to
page 1 from page 2 it is necessary to follow the
procedure outlined in section 3.2.
If an error exists in the data the user will be
reminded by the `Invalid data' message which will
appear at the bottom of the screen. Once EDIT is
selected the cursor will automatically go to the
line containing the error. When the user apes from the EDIT option, the file is
checked for errors and if any are found they are
displayed in a message as before. The user is then
prompted for yes [Y] or no [N] as to whether he
wishes to leave the EDIT option. If no [N] is
selected because an error message has been
displayed by the error analysis, the cursor will go
to the box containing the erroneous value.
3.5 The Insert (INS) Command
This command is used to add data either in the
middle or at the end of an existing data set. The
user is required to enter the line number at which
the new data is to be inserted.
The existing data is automatically re-displayed
showing blank data boxes for that line. The Edit
command is automatically invoked and the user may
move the cursor to the new line and enter the
completion of the data entry the ape key may
be pressed and a re-calculation and error analysis
will check the integrity of the data.enters the required line number and presses , he is then asked to confirm this
choice by yes [Y] or no [N] in answer to the
question `Are you sure?' If [Y] is selected the
deletion is performed.
3.7 The KILL Command
This command is used to delete an entire data file
which has been recalled and is currently
displayed. If the data displayed does not have a
filename (i.e. has not been previously saved) then
a message `No data file to kill' will appear. Once
kill has been selected the user will be required to
confirm the action in response to the message
`Delete (filename)-Are you sure OK? If [Y] is
entered the file is removed from the disc, the
screen and the memor
3.8 The SAVE Command
This option will store data in a user specified disc
file, see section 2.11. Once a filename has been
entered the file will be saved with this name. Care
must be taken not to give the file the same name as
one that already exists as this will overwrite the old
file without any warning. If the user types [DIR] for
a filename a list of all existing filenames will
appear on the screen. However, if the ape is
pressed the save option will be abandoned but the
data will remain on the screen, so that SAVE can be
reselected if necessar
3.9 The MORE Command
Once a file is recalled to the screen the first 50 sets of
data on page 1 are displayed. The MORE option
displays the second 50 sets of data on page 2. If the
MORE option is selected again the first 50 sets of data
are returned to the screen.
3.10 The OPTIONS Toggle Command
This command displays a second menu as shown.
3.6 The Delete (DEL) Command
This allows the user to delete a line of data and
automatically moves all the succeeding data up to fill
the place of the deleted line. The user is prompted for
the line number by the following:
The data will be re-displayed and re-calculated to
check that the new data is valid. When the user
8These menu options are selected in the same
manner as described in section 2 i.e. by entering the
first letter of the option required or by moving the
cursor and pressing the key. This
menu also has an OPTION command which will
take the user back to the first menu.
3.11 The ANALYSE Command
This option calculates layer thickness and CBR
values for the data entered, the processed data
appearing on the screen thus: When the user selects ANALYSE, the program
identifies layer boundaries in the material based on
the rate of penetration, which is an indicator of the
material strength. The sensitivity of this routine can
be adjusted by changing tolerances and the EM value
(see section 3.15).
The results table displays the strength, CBR and
thickness of each of the layers identified by the
program. The layers are zones of constant
penetration rate within the given tolerance and are
shown graphically in Figure 3.1.
Transition zones are defined between layers when the
gradient of the blow/penetration curve changes
gradually over a certain depth thus not permitting the
positioning of a distinct layer boundary.
A bracketed CBR value may appear next to the
calculated CBR value for a layer when the calculated
value is very high. In these cases the bracketed value
is suggested as being more realistic for analysis
The formula used for the CBR calculation is
displayed beneath the table (see Section 4.10).
3.12 The VIEW Command
The VIEW command is used to display analysed data
in graphical form on the screen or to plot it on a
printer or plotter.
When VIEW is selected the following menu
appears on the screen:These options perform the following plots.
(i) Blow-pen: Plots blows versus penetration,
(mm) see figure 3.2.
(ii) mm-blow: Plots a histogram of the
penetration rate in mm/blow
versus depth in mm. No
boundaries are drawn to
distinguish the individual layers
but they may be identified by the
`steps' in the plot, see figure 3.3.
This plot is useful for assessing
the boundary positions chosen by
(iii) CBR: Plots a histogram of CBR versus
depth, see figure 3.4.
(iv) All: Plots all the above on one
drawing, see figure 3.5.
The format of the initial graphics display is
selected automatically. A scale is fixed so that the
complete plot can appear on the computer screen
with a superimposed grid. Thereafter a number of
graphics functions may be used.
A command line listing the various graphics
display options is located at the top right hand
corner of the screen. Each function is selected
simply by typing the appropriate characters.
9 Figure 3.2 Blows versus penetration curve
NOTE: Beware, on the CBR scale values are shown
getting smaller as you move along the "x" axis.
Figure 3.4 California Bearing Ratio versus
10Figure 3.3 Penetration rate versus depth
Figure 3.5 Combination of Figures 3.2,
3.3, and 3.4 3.12.1 I/O: Zoom Functions
The I and O zoom functions allow a zoom-in or
zoom-out on the current plot. Two rates of zooming
are available. Pressing the [I] or [O] keys will zoom
slowly, each step being 0.1 times the original scale,
but zooming can be speeded up by pressing the key simultaneously which doubles the
zooming rate. After using [I] or [O] the new zoom
level is shown in the top left-hand corner of the
screen and, in the case of [I], a dotted box will show
the portion of the plot which will be displayed full
screen when [V] (View) is pressed.
Normally, if a zoom-in is required, CTRL [I] will
be used to zoom-in the large steps and then [I] for
A maximum zoom level of 500 (500 times the
original plot) is the limit for zooming in, and 0.2
for zooming out.
3.12.2 S/D/E/X: Panning Functions
[S], [D], [E] and [X] may be used to pan a new
plot to the left, right, up and down, respectively.
(It should be noted that these are the same as the
Wordstar cursor movement keys). On some
computers, the arrow cursor keys will achieve the
The panning functions will normally be used after
zooming-in to position the window of the new
plot as required.
Two panning steps are available. A `fine'
movement using the [S], [D], [E] or [X] alone and
a `coarse' movement using with [S], [D],
[E] or [X].Panning appears as follows and the new plot may be
displayed by pressing [V] as before.
3.12.3 G: Grid Toggle
[G] may be pressed to apply/remove a grid
overlay: it acts as a toggle.
3.12.4 V: View Plot
To view a plot on screen, press [V]. This would
normally be used after zooming or panning and
the new plot would be of the zoomed/panned
11 3.12.5 P: Print or Plot
The currently displayed plot of the new window, if
zooming or panning has been carried out, may be
reproduced on a printer or plotter by pressing [P].
The computer screen will clear and a `Preparing
Graphics Image' message will appear. On
completion of printing or plotting, the current plot
will be re-displayed on the screen.
3.12.6 ECS: End Graphics
The ape key may be pressed to end
graphics and to return to the option list or
3.13 The PRINT Command
This option prints the data in the following format,
once the user has checked that the printer is ready for
printing and confirmed this to the
3.14 The FILE Command
This option writes the data to a print file in ASCII
format. The format of the file is as follows:The file name is always the same as the data file name.
However, the suffix becomes [FILENAME]. FIL as
explained in section 2.12. These files are used in the
batch print, see section 4.9, and the final printed format
is as shown above.
3.15 The Tolerance (TOL) Command
When the user selects this he will be presented
with the following screen:
The values E1 to E4 along the bottom of the screen
are the tolerances which the program will apply to
particular ranges of penetration/blow gradient
during the analysis phase. These values
12 can be changed by the user. The gradient ranges to
which the tolerances are applied are as follows:
E1 - Tolerance for penetration gradients between
0 and 3 mm/blow
E2 - Tolerance for penetration gradients between
3 and 8 mm/blow
E3 - Tolerance for penetration gradients between
8 and 20 mm/blow
E4 - Tolerance for penetration gradients >20
The EM value at the bottom right of the screen is a
multiplying factor which is applied to each of the
four tolerances allowing the user to manipulate the
sensitivity of the layer identification routine.
EM x the zone tolerance (El to E4) gives the
amount by which the gradient of the
penetration/blow curve is allowed to vary before
the program decides that a new layer exists.
Decreasing any of the zone variables (El-E4)
decreases the tolerance in that zone thereby
increasing the number of layers which might be
Changing the value of EM will affect ALL the
zones as follows:
Decrease in EM - Increase in sensitivity-
Increase in number of layers
Increase in EM - Decrease in sensitivity-
Decrease in number of layers
3.16 Structural Number (SN) Command
For the selection of this option the data file must have
been analysed (Section 3.10). If this has not been
done an error message `Not yet analysed' will appear.
Once analysed this option will display the following:The user must then choose whether he wishes to
use the basic or adjusted structural number
The basic structural number is similar to the original
AASHTO definition but with the addition of the
subgrade contribution. The adjusted structural
number takes account of the way that layer
contributions decrease with depth. This option is
recommended whenever the subbase is thick or
multilayered and whenever the exact definition of
the top of the subgrade is difficult.
Once an equation has been chosen, a prompt will
appear under the layer (B/S/G) column. The user
must either press , which leaves the
field blank, or enter
[B] - Base
[S] - Subbase
[G] - Sub grade
to define the pavement layers. The program then
assigns coefficients to the three layer types for use in
the structural number calculation.
Once layers have been defined, the user is
presented with the following screen:
The program now prompts for the structural number
of the surface layer to be input by the user. This
value, if entered, is simply added to the total for the
other layers specified as base, sub-base or sub-grade.
If any of these layers have not been specified the
user will be prompted to input additional structural
numbers. If a surface layer is not present the field
can be left blank.
Once values have been entered and pressed, the following screen is displayed:
13 Structural numbers for selected layers together
with a total value for the entire pavement are
given along the bottom of the screen.
The suggested CBR values in brackets, see section
3.10, may change according to the designation of the
4. FILE MAINTENANCE
The file maintenance option allows the user to define
which data drive is active, the number of lines per
page for the printer paper and the printer controls. It
also allows him to assign the active graphics devices,
to test the graphics interface and to specify the
graphics parameters. The definable variables are
stored in the file DCPCO and the graphics parameter
file DCPGRF. If the DCPCO file is modified for
colour etc, check the specified parameters.
The following program menu is displayed:
Select the required option using cursor and or the option number. Otherwise press ape to return to the TRRL DCP OPTIONS
LIST. Each of the options is discussed in turn in the
4.2 Assign Data Drive
This option allows the current data drive to be
reviewed with the following message:
Current Data Drive: [C]
Permissible drive letters are A to Z inclusive. Enter
the new drive letter and confirm that the data is OK,
or press to accept the displayed value.
Note that sub-directories cannot be assigned to the
4.3 Paper Length/Beeper Control
This option allows the length of printer paper to be
defined as lines per page. The number of lines per
page is reviewed with the following message:-
14 Number of lines per Page: 
Beeper on [Y]
Most printers use a standard 6 lines per inch, so
computer paper of 11 inches in length will be 66 lines
per page, while A4 paper will be 70 lines per page.
Enter the new number of lines per page and confirm
that the data is OK or press to accept the
The user may also choose whether to have the
beeper on [Y] or off [N].
4.4 Enter Printer Controls
An explanation of how the printer controls must be
entered appears on the following screen:
Having pressed any key the following
screen reveals the current control settings:
The program does not at present make use of all
the printer controls and they are only included to
allow for possible expansion.
The control codes to be used for compressed print
on/off and underline on/off will have to be obtained
from the printer manual and consist of a series of
ASCII values. For each control code, the operator is
required to enter first the number of ASCII
characters in the control sequence and then the
ASCII values of each of the characters. All ASCII
values are entered as decimal integer numbers.
Three further controls are specified.
Margin Shift: This provides a means of setting the
left margin on the printout and is
specified in characters, hence a ½ inch
margin at 12 cpi would require an
input of 6 characters.
Backspace If there was no control sequence for
Underlining: underline on/off for the printer,
then it should be set to [N] and if
the printer is a backspacing
`teletype-like' machine then
backspace underlining can be used
instead by typing [Y]. If there is a
control sequence for underline
on/off, or backspace underlining
cannot be used then type [N].
Vertica This permits a vertical space to be
Shift: left at the top of each form/page.
Enter the number of lines to be left
blank at the top of each page.
Having entered/amended the printer controls the
operator is required to confirm that the displayed
values are to be stored on disc. These values remain
current until they are changed again.
4.5 Assign Graphics Devices
This option allows the system to be configured for
screen and/or plotter/printer graphics.
The following screen is presented:
Only devices which support the Digital Research
GSX/GEM system may be assigned and their
respective drivers must be specified and be
available on the current default disc drive. If the
devices of your system do not support GSX/GEM
graphics then they must be set as not being
available and an entr
y [N] must be made. Otherwise, if the screen or printer/plotter supports
GSX/GEM graphics, enter [Y].
Having assigned the graphics devices, the user
is required to confirm that the data is `OK'
before being returned to the menu.
4.6 Test Graphics Screen
Select this option to check the graphics interface
and to produce a `test card' on the screen. The test
card will contain elements used throughout the
DCP options and will be similar to the following:
4.7 Test Graphics Printer
Select this option to check the graphics interface and
to produce a `test card' on the printer/plotter. The test
card will contain elements used throughout the DCP
options. It should be compared with the screen image
to identify any differences between the two devices.
4.8 Specify Graphics Parameters
This option allows various parameters to be
modified to suit the user's system. The following
screen is presented:The screen aspect ratio and printer aspect ratio
may be specified. These are values between 0.5
and 2.0 to factor the co-ordinates on the relevant
axis to accommodate for distribution. These
values should normally be set to 1.0. However,
should the test card show an incorrect aspect
ratio, then suitable values can be entered to
correct the distortion.
Two further parameters can be defined. These are:
(i) Graphics text size
Changes the size of the text of the graphics
on both the screen and printer. The required
size may be obtained by experimentation.
(ii) Printer Border
The graphical output on dot matrix printers is
often hindered by the need to plot out a border,
so a flag has been introduced. By entering [Y] a
printer border will be included on the plots.
Otherwise entering [N] will not print out a
4.9 Batch Print
Once a data file has been `filed' (see 3.14) it may
be printed as a batch print. Selection of this option
will display the following:
If the user tries to enter a data file which has not
been filed an Error message ‘“filename” not filed’
will appear at the bottom of the screen.
Once the user has confirmed the printer is ready and
correctly set, all the files listed will be printed one
after another, each starting on a new page. It should
be noted that the analysed data is not printed below
the data as in the PRINT command of the Process
DCP Data options (Section 3.13).
16 An example of the format of a file printed by this
method is found in section 3.14.
4.10 CBR Relationships
This option allows the user to choose which
relationship between layer strength and Californian
Bearing Ratio to use. There is a choice of the
The four options are
1. Kleyn equation:
10 (CBR) = 2.632-1.28 x Log 10 (Strength)
2. TRRL equation:
10 (CBR) = 2.48-1.057 x Log 10 (Strength)
3. Expansive clay equation:
10 (CBR) = 2.315-0.858 x Log 10 (Strength)
4. User defined equation:
This option requires a user entered constant
and coefficient in the equation:
10 (CBR) = Constant-Coefficient
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