TABLE OF CONTENTS
Introduction
Sample Problem : Normal Depth for a Trapezoidal Cross Section
Sample Problem : Normal Depth for an Irregular Cross Section
Sample Problem : Channel Capacity for a Rectangular Cross Section
Sample Problem : Channel Capacity for a Triangular Cross Section
Sample Problem : Channel Capacity for a Circular Cross Section
Sample Problem : Step-Backwater for Irregular Cross Sections
Solutions
INTRODUCTION
This document includes six problems with sample data sets for use in the Quick-2
program. These problems are intended to reinforce the information found in the Quick-2
online tutorial and to demonstrate some of the program functionality that was not
discussed in that online resource.
Screen captures illustrating the results for each sample problem can be found in the
"Solutions" section at the end of this document. After completing each sample problem,
you can verify your results with the answers in the "Solutions" section. Look for the
references to the solutions throughout the document.
Sample Problem 1: Normal Depth for a Trapezoidal Cross Section
This sample problem outlines the steps for finding the depth of flow in a trapezoidal
channel. To start this sample problem, select "File" from the pull-down menu bar and
click on "New". Create a new file in the directory of your choice and click the "Open"
button, followed by the "OK" button to open your new file.
Select "Normal Depth" from the "Method" pull-down menu bar and click on
"Trapezoidal" on the fly-out menu. Type "1" as the ID of your Cross Section and
complete the calculation with the input information included below.
1. Manning's n = 0.035 or
2. Slope = 0.005 or
3. LSide Slope (H:V) = 2 or
4. RSide Slope (H:V) = 3 or
5. Bottom Width (ft) = 10 or
6. Discharge (cfs) = 300 or
7. Click the "Begin Calculation" button and scan the newly calculated data in the 'Output
Data' column.
Compare your results with those in the "Solutions" section (Problem 1, Solution 1).
You can view the graphic plots by selecting "View" from the menu bar and following the
steps outlined below.
1. Click on "Rating Curve" to view a Rating Curve plot in a new window
("Solutions": Problem 1, Solution 2).
2. Click on the "Plot Now!" Button to view a Cross Section plot
("Solutions": Problem 1, Solution 3).
3. To Print, click the "Print!" button.
4. Close the graph by closing the window.
You can view the output data report files by selecting "View" from the menu bar and
following the steps outlined below.
1. Click on "Summary Output". The output is shown in a separate file, which can be
viewed using the Windows Write program. You can modify the data and save the file
under a new name and directory. Modifying this file will not affect your main Quick-2
file, which contains the source data for these separate output files
("Solutions": Problem 1, Solution 4).
2. Close the output file by closing the window.
3. Click on "Detailed Input/Output" and view the results
("Solutions": Problem 1, Solution 5).
4. Close the output file by closing the window.
5. Click on "Rating Curve Data" and view the results
("Solutions": Problem 1, Solution 6).
6. Close the output file by closing the window.
Sample Problem 2: Normal Depth for an Irregular Cross Section
This sample problem outlines the steps for finding the depth of flow in an irregular cross
section. You can start this sample problem from the file created in Sample Problem 1, or
you can create a new file for this example. Once you have made your choice, select
"Normal Depth" from the "Method" pull-down menu bar and click on "Irregular Cross
Section" on the fly-out menu. Type "1.1" as the ID of your Cross Section and complete
the calculation with the input information included below.
1. Enter the ground points using the data below:
Stat
362
425
509
512
602
605
732
1020
Elev
505.0
499.1
498.0
496.9
496.9
498.2
500.1
504.7
2. When you are finished entering the ground point data and are sure they are correct,
press the "Save Points" button.
3. EG Slope = 0.0029 ft/ft
4. Channel Bank Stations
Left 509
Right 605
5. Manning's n values
Left 0.065
Channel 0.040
Right 0.060
6. Discharge = 3000 cfs
7. Click the "Compute" button ("Solutions": Problem 2, Solution 1).
8. Click on "File", then click on "Close/Save" to save and close your work.
Sample Problem 3: Channel Capacity for a Rectangular Cross Section
This sample problem outlines the steps for finding the channel capacity for a rectangular
cross section. To start this sample problem, select "File" from the pull-down menu bar
and click on "New". Create a new file in the directory of your choice and click the
"Open" button, followed by the "OK" button to open your new file.
Select "Channel Capacity" on the "Method" pull-down menu bar, then click on
"Rectangular" from the fly-out menu. Type "1" as the ID of your Cross Section and
complete the calculation with the input information included below.
1. Manning's n = 0.035
2. Slope (ft/ft) = 0.01
3. Bottom Width (ft) = 10
4. Depth (ft) = 5
5. Click the "Begin Calculation" button and scan the newly calculated data in the
'Output Data' column.
Compare your results with those in the "Solutions" section (Problem 3, Solution 1).
Once you are finished viewing the output on the screen, you can view the different graph
and report options that are available by Clicking on "View" from the main menu bar.
Sample Problem 4: Channel Capacity for a Triangular Cross Section
This sample problem outlines the steps for finding the channel capacity for a triangular
cross section. To start this sample problem, select "File" from the pull-down menu bar
and click on "New". Create a new file in the directory of your choice and click the
"Open" button, followed by the "OK" button to open your new file.
Select "Channel Capacity" from the "Method" pull-down menu bar and select
"Triangular" from the fly-out menu. Type "12.1" as the ID of your Cross Section and
complete the calculation with the input information included below.
1. Manning's n = 0.015
2. Slope (ft/ft) = 0.02
3. LSide Slope (H:V) = 5
4. RSide Slope (H:V) = 3
5. Depth (ft) = 3
6. Press the "Compute" button ("Solutions": Problem 4, Solution 1).
Notice the warning message ("Solutions": Problem 4, Solution 2). FEMA does not
accept supercritical depth elevations for use in determining Base Flood Elevations (unless
the channel has been specifically designed to operate under supercritical flow conditions).
The critical depth elevation should be used instead
("Solutions": Problem 4, Solution 3).
Once you are finished viewing the output on the screen, you can look at the different
graph and report options that are available by clicking on "View" from the main menu
bar.
Sample Problem 5: Channel Capacity for a Circular Cross Section
This sample problem outlines the steps for finding the channel capacity for a circular
cross section. You can start this sample problem from the file created in Sample Problem
4, or you can create a new file for this example. Once you have made your choice, select
"Channel Capacity" from the "Method" pull-down menu bar and select "Circular"
from the fly-out menu. Type "12.2" as the ID of your Cross Section and complete the
calculation with the input information included below.
1. Manning's n = 0.013
2. Slope (ft/ft) = 0.005
3. Diameter (in) = 36
4. Depth (ft) = 3
5. Press the "Begin Calculation" button and scan the newly computed data in the
'Output Data' column ("Solutions": Problem 5, Solution 1).
You can view the graphic plots by selecting "View" from the menu bar and following the
steps outlined below.
1. Click on "View" from the menu bar.
2. Click on "Rating Curve" to view the Rating Curve plot in a new window
("Solutions": Problem 5, Solution 2).
3. Click on the "Plot Now!" button to view the Cross Section plot, which is just a circle
in this case ("Solutions": Problem 5, Solution 3).
Notice that the rating curve "tails back in" to the left. This happens because maximum
flow in a pipe actually occurs at approximately 95% full flow. As the pipe flows above
95%, the increase in the friction loss in the pipe actually reduces the amount of discharge
it can carry.
Sample Problem 6: Step-Backwater for Irregular Cross Sections
This sample problem outlines the steps for completing a step backwater calculation for
irregular cross sections. To start this sample problem, select "File" from the pull-down
menu bar and click on "New". Create a new file in the directory of your choice and click
the "Open" button, followed by the "OK" button to open your new file.
Select the "Method" pull-down menu bar, then click on "Step-Backwater" from the fly-
out menu.
CROSS SECTION # 1
Type "1" as the ID of your Cross Section and complete the calculation with the input
information included below.
1. Enter the ground points using the data below:
Stat
362
425
509
512
602
605
732
1020
Elev
505.0
499.1
498.0
496.9
496.9
498.2
500.1
504.7
2. When you are finished entering the ground point data and are sure they are correct,
press the "Save Points" button.
3. A dialog box pops up giving you information about how to begin your initial
calculation. Once you click "OK" the cursor will be in the 'WS Elev' text box. For
this Step-Backwater analysis, we will begin the initial calculation using an EG
(Energy Grade) slope, which approximates the downstream channel slope
("Solutions": Problem 6, Solution 1).
4. EG Slope = 0.0029 ft/ft
5. Channel Bank Stations
Left 509
Right 605
6. Manning's n values
Left 0.065
Channel 0.040
Right 0.060
7. Discharge = 3000 cfs
8. Click the "Compute" button ("Solutions": Problem 6, Solution 2).
CROSS SECTION # 2
To add another cross section to this Step-Backwater analysis, click the "New X-Sec"
button and repeat the above procedure using the data below.
(Note that for this next cross section, when you Save your ground points, the cursor will
be at the Channel Bank Stations text box, since you do not have to input starting water
surface elevation or slope data after the first cross section).
1. Type "2" as the ID of your Cross Section, and press .
2. Enter the ground points using the data below:
Stat
1
150
233
236
331
334
402
591
Elev
510.0
504.8
502.2
500.9
500.9
501.8
505.5
510.1
3. When you are finished entering the ground point data and are sure they are correct,
press the "Save Points" button. Note that the cursor is now inside the Left Channel
Bank Station text box. This is because, after the first cross section, you do not have
to put in a starting water surface elevation or slope.
4. Channel Bank Stations
Left 233
Right 334
5. Manning's n values
Left 0.055
Channel 0.040
Right 0.060
6. Reach Lengths
Left 450
Channel 450
Right 450
7. Discharge 3000 cfs
8. Click the "Compute" button and scan the newly computed data. (Note that there is a
critical depth message in the message box. This indicates that the program could not
arrive at an energy balance, and so had to compute the critical depth at this section)
("Sections": Problem 6, Solution 3).
CROSS SECTION # 3
To add another cross section to this Step-Backwater analysis, click the "New X-Sec"
button and repeat the above procedure using the data below.
1. Type "3" as the ID of your Cross Section, and press .
2. Enter the ground points using the data below:
Stat
1
433
600
614
701
725
866
1240
Elev
512.0
510.1
506.3
504.9
504.8
506.5
511.1
512.1
3. When you are finished entering the ground point data and are sure they are correct,
press the "Save Points" button.
4. Channel Bank Stations
Left 600
Right 725
5. Manning's n values
Left 0.065
Channel 0.040
Right 0.060
6. Reach Lengths
Left 490
Channel 490
Right 490
7. Discharge = 3000 cfs
8. Click the "Compute" button and scan the newly computed data
("Solutions": Problem 6, Solution 4).
Now run this Quick-2 computation using the HEC-2 program. To do this, first select
"File" from the pull-down menu bar and click on "Save / Run As HEC-2 File". You
will be asked for a new name for the HEC-2 file input file. To keep it simple, just keep
the same file name that you are using but change the extension to ”.dat” . This file is now
in HEC-2 file format. Click on "Save" then "OK" to save the file.
Select "HEC-2 Output" in the "View" pull-down menu bar to run the HEC-2 program in
a DOS window ("Solutions": Problem 6, Solution 5). When the calculation is
complete, you can close that window. The HEC-2 results will appear as an output file
(hec2.out) in the Write program. You may view the file ("Solutions": Problem 6,
Solution 6) and save it under a different directory or name just like any other text file.
Note that to print all of the data so that they fit the width of the page, you may have to
select all of the output and change the font size to "8" and the page orientation to
"landscape".
Once you are finished viewing the HEC-2 output file, close the Write program, click on
"File", and then "Exit" to close the program.
SOLUTIONS
Problem 1: Normal Depth for a Trapezoidal Cross Section
Solution 1:
Channel - (Normal Depth Method) Window
Solution 2:
Rating Curve - Cross Section 1 Window
Solution 3:
Plot - Cross Section 1 Window
Solution 4:
Summary.qk2 - WordPad output file - Cross Section Data
Solution 5:
Summary.qk2 - WordPad Output File - Cross Section Diagram, Input and Output Variables
Solution 6:
Summary.qk2 - WordPad Output File - Detailed information for Cross Section 1
Problem 2: Normal Depth for an Irregular Cross Section
Solution 1:
Quick-2, Version 2.0, Interface - Information for Cross Section 1.1
Problem 3: Channel Capacity for a Rectangular Cross Section
Solution 1:
Normal Depth Analysis - (Channel Capacity Method) - Information for Cross Section 1
Problem 4: Channel Capacity for a Triangular Cross Section
Solution 1:
Quick-2, Version 2.0 - (Channel Capacity Method) - Information for Cross Section 12.1
Solution 2:
Super-Critical Warning Window: FEMA does not normally accept Super-Critical Elevations to establish Base Flood Elevations. Use the Critical Depth Elevation instead.Solution 3:
Quick-2, Version 2.0, Interface - Channel Capactity Method - Information for Cross Section 12.1
Problem 5: Channel Capacity for a Circular Cross Section
Solution 1:
Step-Backwater Analysis - (Channel Capacity Method) - Information for Cross Section 12.2
Solution 2:
Rating Curve Window - Cross Section 12.2
Solution 3:
Plot Window - Cross Section 12.2
Problem 6: Step-Backwater for Irregular Cross Sections
Solution 1:
Solution 2:
Starting Condition for Step-Backwater Computation - You may start your computations by entering a know Water Surface Elevation (WS Elev) or Depth; or by the Normal Depth Method, by entering an EG Slope. OK Button.Normal Depth Analysis - (Step-Backwater Method) - Information for Cross Section 1
Solution 3:
Save File - (Step-Backwater Method) - Information for Cross Section 2
Solution 4:
Step-Backwater Analysis - (Step-Backwater Method) - Information for Cross Section 3
Solution 5:
Finished - h2: DOS Window - This window indicates the water-surface elevation for each cross section in the modelSolution 6:
Hec2.out - WordPad Output File - This is the output file for the model in HEC-2 format