Tutorial 23

In this Tutorial you will learn

¨ To locate a Design Platform horizontally within a model.

¨ To set the platform at a desired design height.

¨ To apply batter slopes from the edge of the platform to the model.

¨ To calculate the volume of material to be moved to construct the platform.

¨ To adjust the design height of the platform to balance the earthworks.

Base data has been supplied in a Job with an ID of "Platform”

Start Ezicad and use File Open to open platform.CDSdb located in the Ezicad_Premium\tutor folder

Pull down the Contour menu, and use Surface Parameters to make sure the values for Surface 1 make some sense.

Next form the model and contour the surface that should appear as below.

The client requires us to position a level pad with dimensions 180 metres by 100 metres to use for standing a dragline, and the earthworks should be close to balanced with a small excess of cut being preferable.

In this instance we have examined an existing contour plan of the site, and in the time honoured method of design we have pencilled in a rough area where we would like to place a pad, and scaled off one of the corners.

The bottom left hand corner of the pad should have coordinates of East 8690 and North 7540 and the long side of the pad is on a bearing of 330 degrees.

As a preliminary estimate, we think that a finished level of the pad of 225 might be somewhere near the mark.

How you arrive at the horizontal location of your pad is largely irrelevant,

and beyond the scope of these tutorials to deal with ... all that is important is that you locate it somewhere.

Our first task is to calculate the points on the corners of our proposed pad, and give them our trial RL of 225.

Use the Modes Icon (or F9) to pull down the Modes Screen.

Now select the Tab titled Modes-Input, and the screen at left should appear.

Move the cursor down to the line "Prompt for Design Height", and select the radio button titled Constant. Now enter a constant value of 225.

Now press OK to return to the Ezicad screen,

Pull down the Points menu and select Add Points - you will notice that your cursor changes to a cross.

Position it somewhere on the model and select a point.

When the Add/Edit/Query box appears, enter a Point Number of 500, and Easting of 8690, Northing of 7540 and a you will see that a Design Height of 225 has already been set for you.

Select OK, and Point 500 will appear on the screen.

Now pull down the Points menu and turn Add Points Off (or press the Escape key to achieve the same ‘off switch’) and the cursor will revert to the normal pointing arrow.

Next pull down the Cogo menu and select Calculate by Bearing and Distance.

Enter 500 as the point to start from followed by 330 for the bearing and 180 for the distance. Select Apply and you will see point 501 appear.

To get the next point, position the cursor in the “bearing” field and press the ‘R’ key to add 90 degrees to the current bearing.

Tab to the Distance field and enter 100, then select Apply to create Point 502.

Again move to the bearing field, press ‘R’ and then enter the distance of 180 and Apply to create point 503, which is the final corner of our pad.

It is a requirement that the pads or platforms are defined in a String Folder with a name of "PAD".

Pull down the Strings Menu and select Add.

If necessary, drag the Strings box down to the bottom right hand corner so it is clear of the area where the pad is located

Use an ID of P1 to identify the particular string defining the edge of the platform.

Position the cursor in the ‘folder field’ and Type in ‘pad’ for the folder name.

Note that it doesn’t matter whether you try and use upper case or lower case, the program will convert everything to lower case as you enter the Folder name. This is necessary to avoid some slight confusion between file or folder naming conventions in different version of Windows.

Accept the default pen and linetype.

Move the cursor into the string entry field, and either type in the string 500,501,502,503,500, or use your mouse to select the points.
(The more astute among you may have remembered that a sequence of points such as this could have been typed in as 500.503,500)

At the end of the process your screen should be similar to the one shown adjacent.

Use Strings, Select, Select All to ensure that this string is selected.

Now pull down the Contour Menu, Select the option titled Interpolate, and then the option titled Profiles and Sections.

The Setup Interpolation table will appear.

Change the column headed “Xs St” which is shorthand for ‘cross section interval to interpolate along a straight section of the string’ to 10.

.

Select the button ‘Refresh Table’ and you will see a list of the section to be interpolated are loaded into the table.

Now select the ‘save’ button and wait while the data is interpolated.

The screen will appear similar to that seen at left.

Click ‘OK+Save’ and you will be notified that the interpolated points have been added to string ‘pad p1’.

Click OK to end, and then Cancel to exit from the Interpolation screen.

The next step is to display the profile along the edge of the pad. Select road works and interactive design, or the Profile icon to see the screen at right with the profile shown.

At present the design level of 225.0 is not shown.

Right click within the view and select Option titled Design

Points to Design.

You should now have a design line at height 225.0 displayed.

We now wish to view the sections, so click on the Display Section Icon to see the screen below.

We now wish to display a bank on the outside of the pad. Right click and select the Predefined Templates option.

Select the batter template.

Click left edge only and fill in 50% for the Cut and Fill.

After selecting OK the program sets up all internal tables to display this bank at each section.

If you now pick the Next button you can scroll through the sections, and you will see the batter appearing.

Select Window followed by Tile Road Works option to display all three views at once.

Highlight the Plan view, pull down the Contour menu, and select Surface Parameters.

Select the button on the right hand side titled Add, and the screen will appear as below.

Select the radio button titled Design to indicate that it is a design surface that we wish to add and then select OK.

Now pull down the Road Menu, select the Design Surface option, followed by Store Design Points.

Select a road number of 1 and change the next point number to 600.

Add in a string name of ‘paddesign’ and run the option. The points are added into the database.

Depending on your computer, this process might take a little while, so please be patient and don’t start hitting buttons of trying other options.

When the pop up window clears you will see a new series of points have been added.

Now select Contour followed by Form Model.

Next Calculate the Contours and if you let them save, you should end up with a display as shown at left.

If you do not have contours resembling those in the screen then you need to go back and re-trace your steps until you do.

Once the Design contours are satisfactory, you need to determine a volume of earth to be moved to construct this pad.

Pull down the Contour Menu, select Volumes, and the select Surface to Surface.

The Base Surface is Surface 1 which is the natural Surface, and you will need to change the Overlay surface to be Surface 2 which is your design surface at the moment.

Once you have the surfaces correctly assigned, press the OK button, and you will soon see the answer appear in Word/Wordpad which reveals some 50,000 metres of fill and 13,000 metres of cut.

It is obvious that we have far too much fill in this instance, so we need to drop the proposed level of the pad.

The first thing you need to do is to delete the points that were calculated for the first attempt at the pad since they are no longer useful.

So, pull down the Points menu and pick the Select option. Then choose Select by Range.

The following screen will appear, and the easiest way to achieve the range you need is to select the All button on the Point Number line, then alter the start of the range to be 600, and then select OK.

You will see all the selected points appear in dark numbers.

Pull down the Points menu again, and this time select the Delete option.

All the selected points will now be deleted from the screen.

You should also note that even though the design points are gone from the job, the design contours will still be displayed until you form them again.

Now, in an attempt to balance the cut and fills for this job we have already established that we need to drop the pad, and using the time honoured method of educated guesswork, I suggest that you drop it by 1.5 metres and see what eventuates.

To achieve this, make the profile view active.

Right click your mouse to bring up the options. Select the option called Up – Down and fill in a value of “-1.5”.

You will see the design line drop 1.5 metres on your profile view.

Now choose Road > Design Surface > Store Design Points to place the design points into the database as before.

Again use a point of 600 with a road number of 1.

Once the points are calculated and stored, pull down Contour, select Surface Parameters and make Surface 2 current.

Now Form the Model and calculate and save the contours..

Once that is done, it is time to again calculate a volume and see how close to balance we have come.

Pull down Contour, choose Volumes and Surface to Surface, and make sure that the Overlay Surface is set to Surface 2.

If you see a Fill Volume of some 29,000 cubic metres and a cut volume of around 26,000 cubic metres we will consider it to be close enough for the purposes of the exercise.

You should now be aware of the procedure, which is more important than the numbers we use in any of these examples.

Before we proceed, you need to be aware that the program has stored the string around the outside of the design surface in a String Folder named “paddesign”, and you can use this for slope staking, plotting etc.

The next thing we wish to do is to form up a Combined Surface which will show us the contours after the pad has been built ( An “As-Built” , or “As-Constructed” if you like).

Pull down Contour, choose Surface Parameters and choose Add to create Surface 3, and make it a Combined Surface.

Make sure Surface 3 is current and press OK.

Now pull down the Contour Menu and choose Merge Surfaces.

Accept the default Base Surface of Surface 1, Overlay surface of Surface 2 and Merged Surface of Surface 3.

You will see that the program goes off and automatically forms the combined model for you.

If you now Calculate the Contours, save them and get rid of the triangles from the display you should achieve a result as seen below.

If you maximise the Plan window and turn off all the extraneous numbers etc, you can see the result below.

Note we have only used one platform in this example, but you can define more than one in the “pad” folder if you wish, and they will be processed sequentially.