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Designing a building pad and dam

In preparation for the next part of the tutorial you should create another file to work with.

 

Note: If you have taken a break between tutorial sections, you first need to Open the appropriate file.

* Open the file named Tutorial Part 4.rdd.

 

* Choose Save as... from the File menu.

* Name the file Tutorial Part 5.rdd.

You will now learn how to design a building pad and a dam. There are three main elements in designing a building pad:

* specifying its shape, size and location

* determining its interaction with the natural surface

* modelling the terrain after the design is completed.

Each building pad you design is represented by a control line. Despite the name, building pads can represent construction works other than building pads. You can design dams, quarries, or any other earthworks that need a flat area with slopes up and down to the existing surface.

* Choose Fit to window from the View menu.

* Choose New control line... from the Plan menu.

A dialog box as shown in Figure 2-30 will appear.

* Type House pad in the space provided next to Name.

* Click Building pad.

* Click OK.

This tells HighRoad that you want to design a building pad named House pad. The initial dimensions of the building pad will be a rectangle 15 m by 25 m.

 

Figure 2-30

 

You can now position the building pad on the terrain model. The cursor will change to a cross when it is over the Plan window.

* Drag the cursor, being sure to remain entirely within the terrain model while dragging.

A rectangle of the size of the pad will appear centred on the cursor.

* Continue to drag the building pad until it is halfway between point number 2 and point number 8.

* Release the mouse button when the building pad is positioned at the desired location.

The building pad (including batter slopes) will be drawn on the screen as shown in Figure 2-31.

 

Figure 2-31

* Move the cursor so that it is over the building pad.

The cursor will change to a hand shape () which indicates that you can drag the pad.

* Drag the pad to different locations to see how the batter slopes are redrawn to suit the terrain in the new location.

When you have finished return the building pad to the position shown in Figure 2-31. The location of the pad in Figure 2-31 is very close to the boundary line between point 7 and 8 and the batter slope is very close to the boundary. The building pad would fit better in this area if the width and length were swapped, and its orientation aligned with the boundary.

* Double-click on the pad when the cursor is a hand shape.

A dialog box will appear as shown in Figure 2-32. This is similar to the dialog box shown in Figure 2-30 but with additional information about the elevation and orientation of the building pad.

 

Figure 2-32

* Change the width to 25 m and the length to 15 m.

* Set the elevation to 37 m.

* Set the orientation to 10 degrees.

* Click OK.

Note: You could achieve the same position simply by adjusting the orientation to 100 degrees.

The building pad will be redrawn in the new position.

 

Estimating earthworks quantities

* Note the direction of the rills on the batter slope.

Rills are always attached to the high end of the batter slope. In this example, the building pad is almost entirely in fill as can be seen from the direction of the rills on the batter slopes, which are attached to the pad and slope down towards the ground.

You can see the volume of earthworks required for this building pad by displaying the Text window and listing the earthworks.

* Choose Text from the Windows menu .

An empty document will be displayed.

* Choose List Quantities from the Text menu.

The earthworks will be shown as no cut and about 480 m3 of fill.

 

Note: The volume listed in your example may be slightly different because the location of your building pad may not be exactly the same.

* Choose Save... from the File menu.

 

Note: If you have HighRoad S, only one pad can be designed for each project. To follow this tutorial open the file Tutorial Part 2.rdd again. As you proceed with the tutorial please note that the first pad will not be shown.

 

Designing a dam

* Choose New control line... from the Plan menu.

* Name the pad Farm dam.

* Select Building pad to specify the type of control line required.

* Change the width and length to 20 m.

* Click OK.

 

The cursor will change to a cross when it is over the Plan window so you can now position the dam.

* Drag the dam to the left (west) and down hill from the house pad between point numbers 8 and 9.

* Release the mouse button when the building pad is positioned at the desired location.

 

The dam (including batter slopes) will be drawn on the screen. The ground level near the dam is approximately 34 m. The pad elevation (i.e. the bottom of the dam) needs to be below ground level.

* Double-click on the dam.

* Set the elevation to 33 m in the dialog box that appears.

* Click OK.

* Look at the batter slope on the southwest corner of the dam.

 

Figure 2-33

 

The narrow batter slope (as shown in Figure 2-33) indicates that the ground level near this corner of the dam is much lower than around the rest of the dam. The maximum water level you could have in the dam is limited by this low level. To allow for a greater water capacity you can create an earth wall around part of the dam where the ground is lower. To do this you need to change the typical section of the dam. The typical section determines the interaction of the building pad (in this case, the dam) with the natural surface.

 

Creating a dam wall

When a building pad is first created it is assigned a simple typical section shape which allows for a batter slope of 50% for both cuts and fills. In the case of the dam you need to allow a similar arrangement when the dam is in cut, but provide for a dam wall when it is in fill, or only just below the ground level. The height of the wall will be determined by the minimum depth of the dam required. In this case the required depth is 2 m therefore the minimum wall height required is 2 m above the bottom of the dam. If the dam floor is 2 m or more below ground level, a batter slope (as described above) up to the ground is required. When the dam floor is less than 2 m below the ground, or above the ground, a wall is required. The wall width will be 2 metres and batter slopes of 50%.

* Select Typical Section from the Window menu.

 

Figure 2-34

 

A window named Farm dam Typical Section 1 of 1 will appear on your screen (see Figure 2-34). The marker in the centre of the window represents the control line for the dam, with the dot representing the level of the control line and the point at which the batter slope attaches. The typical section shown is the standard one which allows for a batter slope of 50% for both cuts and fills. The right side of the typical section represents the flat surface of the pad and left side represents the slopes up and down to the ground surface. You need to replace the down batter slope with a set of links that go up 2 metres and across 2 metres before the down slope is commenced. First you need to undo some of the existing links.

 

Designing a different typical section

* Choose Undo twice to remove the two batter slopes.

Note: If you choose Undo more than twice, the dot representing the level of the control line and the point at which the batter slope attaches will disappear. This dot (split point) must be in place before you can proceed. See Chapter 23, Troubleshooting, Plan view problems.

* Click on the cross cursor () to select it.

The cross cursor is used where no edge type is required.

* Click the untreated surface () to select it.

This generic surface type is used where an untreated surface type is required.

* Position the cursor to the left of the control line. Drag the cursor to a position 4 m to the left of the control line with a crossfall of 50.0%.

* Release the button when the slope is in the right location.

 

Note: If you release the button before the link is located correctly you can change it. Click on the offset and crossfall of the slope you have drawn. A dialog box will appear. You can type in the required offset and crossfall.

Your typical section should now be similar to Figure 2-35. The next task is to add a horizontal link of offset 2 metres. This will be link number 4. (Links are numbered in the order in which they are entered.)

Note: Building pad typical sections have two very short links of 1 mm each attached to the control point. The links you add will be numbered starting with 3.

Figure 2-35

* Position the cursor and drag it to the correct location (2 m offset, 0.0% crossfall).

The next task is to add a batter slope down at 50%. This will be link number 5.

* Click on the batter slope ().

* Add a batter slope down at 50%.

 

Note: If you make an error while setting up the typical section, correct it.

* Choose Undo from the Edit menu.

You have added 3 links so far. Your typical section should now be similar to Figure 2-36. If the dam floor is above the ground level, or as much as 2 metres below the ground level a wall will be created. You now need a batter slope to cover the case when the dam floor is more than 2 metres below ground. This is simply a slope up at 50%.

 

Figure 2-36

* Click on the batter slope () again.

* Add a batter slope up at 50%.

You have now completed the typical section. You should now have a typical section similar to Figure 2-37.

 

Figure 2-37

 

* Choose Plan from the Window menu.

* Examine the dam.

Figure 2-38

You can see in Figure 2-38 that a dam wall has been inserted where the ground level is not high enough to allow the full 2 m depth. The extent of the dam wall is easy to see from the 2 m wide flat strip on top of the dam wall, with batter slopes running down either side of this. The batter slopes from the wall overlap the southern property boundary. The location of the dam can be dragged and/or the orientation changed until it fits within the boundary.

* Double-click on the dam to change the orientation to 10 degrees.

* Drag the dam so that its batter slopes do not encroach on property boundaries (as shown in Figure 2-39).

To assess the cost of construction of this project you can look at earthworks volumes of both the house pad and the dam. By adjusting the position, orientation and elevation of the dam and/or the house pad you can change the quantities until they are balanced, thus minimising the cost of construction.

 

Estimating the water volume of dam

The water volume can be estimated by using a road control line to represent the water surface.

* Choose New control line from the Plan Menu.

* Name the control line Water surface.

* Select Road as the type of control line.

* Click OK.

The control line for the water surface is to go from left to right across the dam, from the middle of the dam wall on the left, to the top of batter slope on the right, as shown in Figure 2-39.

 

Figure 2-39

 

* Choose New IP from the Plan menu.

 

The cursor will change to a cross.

* Click to place the left end of the control line on the dam wall.

* Choose New IP again.

* Click to place the right end of control line near the top of the batter slope.

The elevation of this control line will be the water level. Recall that the floor of the dam is elevation 33 m, and the walls are 2 m high. Allowing for 200 mm freeboard this would mean a water level of 34.8 m. Create a design profile for a water level of 34.8 m.

* Choose Profile from the Window menu.

* Choose Show IP Location from the Profile menu.

* Choose New IP from the Profile menu.

* Locate the first IP at chainage 0 and elevation 34.8.

* Locate the second IP past the end and at elevation 34.8.

* Double-click each IP if necessary to precisely locate it.

 

The profile should appear similar to Figure 2-40. The shape of the dam is not yet shown in the profile.

 

Figure 2-40

 

Construct the dam

To calculate the water volume, the dam needs to be constructed. This will incorporate the shape of the dam into the natural surface. Before you do this, save the work you have done and then make a copy of it to use for constructing the dam.

 

* Choose Save from the File menu.

* Choose Save as... from the File menu.

* Name the file Tutorial Project 5 constructed.rdd.

* Choose Farm Dam from the Active menu.

* Choose Construct Farm Dam from the Plan menu.

* Click Construct.

* Choose Contours... from the Plan menu.

* Set the interval to 0.2 minor and 1.0 major.

* Observe the new contours showing the dam.

* Choose Water surface from the Active menu.

* Choose Profile to see the new shape of the ground surface.

 

The new ground surface is clearly evident in Figure 2-41 in both plan and profile.

 

Figure 2-41

Calculating the volume of water

To calculate the volume of water you need to design a suitable typical section design.

 

* Choose Typical Section from Window menu.

* Choose Clear Typical Section from Typical Section menu.

* Select the cross cursor () as the edge type.

* Select the untreated surface () as the surface type.

* Draw a horizontal link 1 m each side of control point.

* Add a split point on each side.

* Select the batter edge type.

* Draw a horizontal batter each side.

* Click on the chainage range and change to 0 - 1000.000.

 

The typical section should look like that shown in Figure 2-42. The typical section is designed to represent a horizontal surface. The batter slopes will extend horizontally until they strike the dam wall. To verify this inspect some cross sections.

 

Figure 2-42

* Choose Cross Section Plot from the Window menu.

* Click Next and Previous to see the cross sections.

 

Figure 2-43 shows an example of a cross section at chainage 10.000 m.

Figure 2-43

To estimate the water volume, calculate the earthworks quantities for this control line. In this case the fill volume will represent the water.

* Choose Schedule of Quantities from the Window menu.

* Choose Limits from the Quantities menu.

* Click OK.

The full extent of the control line will be used.

The quantity listed as Borrow to Fill is equivalent to water volume (see the Schedule of Quantities in Figure 2-44).

These quantities are based on cross sections at 5 metre intervals. If you require more precision, go to the cross section plot window and set the cross section interval to a smaller value, such as 1 metre.

* Choose Save from the File menu.

 

Figure 2-44

 

Printing your design

To print, plot or export your design, you can use the drawing manager to layout the drawing sheets. See Chapter 17, Drawing production for details. To plot or print this design, see Chapter 18, Printing and Chapter 19, Plotting.

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