L AB E XERCISE : C OORDINATE G EOMETRY

Accessing COGO

1. Open the MicroStation file c:\data\geo\sc219\sc219pp.dgn.

2. Access ProjectManager.

It should automatically access the Road workflow dialog since we “remembered” the options in Lab 2.

3. Select the Coordinate Geometry tool from the Road Project dialog. The dialog below should appear.

This dialog is completely re-sizable, so you can position it where you’re most comfortable.

Import Survey Data to GPK File

1. Set the visualization choice to Disable Visualization.

2. Select File > Input File Restore from the Coordinate geometry window.

3. Select Edit > Read All to process the file.

4. Open the COGO Navigator to verify the points and survey chains are now stored in the GPK file. (Tools>Navigator)

Lab Exercise: Coordinate Geometry

5. Select Edit > Clear to clear the COGO commands from the input file buffer.

6. Select View > Command Output > Clear to empty the output window.

Hint Instead of steps 5 and 6 above, you could close and re-open the COGO dialog for the same

Lab Exercise: Coordinate Geometry

Store an Alignment

Lab Exercise: Coordinate Geometry

1. Select TemporaryVisualization on the main COGO dialog.

2. Select the Store Point tool (COGO: Element >Point > Store).

3. To store point 3100, enter the point number and coordinates as indicated in the dialog above.

4. Activate the Auto Increment toggle.

This will automatically increment the point number by 1 for subsequent Store Point

commands.

5. Click Store Point.

This stores the point into the COGO database.

6. Store Point 3101 using the coordinates shown below.

Lab Exercise: Coordinate Geometry

8. Store Point 3103 using the coordinates shown below.

9. Store Point 3104 using the coordinates shown below.

Lab Exercise: Coordinate Geometry

11. Store Point 3106 using the coordinates shown below.

12. Store Point 3107 using the coordinates shown below.

Lab Exercise: Coordinate Geometry

Store Curve Commands

1. Access the Store Curve By Tangents dialog by pressing the Store Curve By Tangents icon

or by selecting Element >Curve > Store > By Tangents from the COGO dialog. The dialog below should appear.

2. To store the curve SC219R-1, complete the dialog as shown below.

3. Click Store Curve to store curve SC219R-1 into the COGO database.

4. Store the remaining curves using the information provided on the alignment diagram and the images below..

Note Be careful to name each curve uniquely as the only the Store Point tools increment the

Lab Exercise: Coordinate Geometry

5. Dismiss the Store Curve By Tangents dialog by clicking the X in the upper right hand corner.

Store Chain Command

Store the centerline chain SC219R according to the diagram on page 4-21.

1. Access the Store Chain From Elements dialog by pressing the Store Chain From Elements

icon

or by selecting Element >Chain > Store > From Elements. The dialog below should appear.

2. Enter SC219R for the Chain Name.

3. Set the option button to BeginStation and enter 87+25.49.

4. Build the list of COGO elements which will become a part of the chain.

You can fill in the elements comprising the chain by keyin or by graphically selecting the visualized elements in the design file. Ensure that the elements are added to the list in the order that you want them to be stored as a chain. The dialog should appear as below.

Lab Exercise: Coordinate Geometry

5. Click Store Chain to store chain SC219R into the COGO database.

6. Dismiss the Store Chain From Elements dialog by clicking the X in the upper right hand corner.

Describe Chain Command

From the COGO dialog window, let’s preview the chain SC219R coordinate geometry. 1. Access the COGO Navigator dialog by pressing the Navigator icon

or by selecting Tools >Navigator. The dialog below should appear.

Lab Exercise: Coordinate Geometry

Lab Exercise: Coordinate Geometry

The chain geometry will be displayed in the main COGO window as below.

Lab Exercise: Coordinate Geometry

Create Input and Output Files

In the following steps we will save an input trail of our commands and an output file with the computations of chain SC219R.

1. Access the File Utility dialog by pressing the File Utility icon

or by selecting File >File Utility. The dialog below should appear.

2. On the File Utility dialog, set the option button to Save.

3. Enter “SC219” for the Name and “Chain SC219R” for the Subject then click Apply. The saved file will be called ‘SC219839.i36’

Lab Exercise: Coordinate Geometry

4. To save an output file with the actual results of the computations, set the option button to

Output on the File Utility dialog.

5. Output File should be set to SC219.

6. Toggle on “Redefine” on the main COGO dialog.

7. Click Apply. The saved file will be called ‘sc219839.o36’. 8. Toggle off “Redefine” on the main COGO dialog.

9. Dismiss the File Utility dialog by clicking the X in the upper right hand corner.

Working Alignment

Now that we have our alignment, we have another piece of information for the Working Alignment definition.

1. Access the Project Manager Road workflow dialog.

2. Click Define.

3. Highlight Plan View.

4. Click Select and select chain SC219.

Lab Exercise: Coordinate Geometry

Store Chain for Interstate 26

1. Store points for the control points on the chain above. Begin with point number 3111.

2. Store curve I26 using the information provided above.

3. Store chain I26 consisting of the one curve and two points.