Cracking dams
intro

WebQuest

for the Intermediate level
groups of 3
on arch dams



[quest] [tasks] [roles] [process] [worksheet] [conclusion] [for the teacher]



Quest(ion)

Your group's quest is to learn about the services and problems of dams, perform a simulation of cracking in an arch dam, and estimate the loss of life if a dam fails. At the end, you must decide if the services dams provide are more important than the problems dams cause.


Tasks

  • Assign a role to each person in your group.

  • Follow the process below.

  • Post messages on the bulletin board as directed.

  • Answer the questions on your worksheet as you proceed.



  • Roles

    Each of these roles are civil engineers who work for different organizations. Each member of the group should pick a role and then lead the group in the tasks listed for that role.
  • Safety Association Engineer: You are concerned with the services and environmental problems of dams. You lead the group in looking at these two impacts of dams.

  • Bureau Engineer: You are concerned with the simulation of cracking in dams. You lead the group in gathering the tools for a simulation and performing the simulation.

  • Army Corps Engineer: You are concerned with dam statistics. You lead the group in gathering the information about a dam from the National Inventory of Dams and in estimating the loss of life if that dam fails.


  • Process

    Bookmark the WebQuest. Each step of this Process provides a link to different sections in the Cracking Dams web site to help you complete your quest. You should return here after each step.

    1. Assign each person in your group a role from the Roles section. Each person is to become the expert in his or her role.

    2. Go to the National Inventory of Dams (#). Search for an arch dam your county. Directions on how to search are on the worksheet. In the database, gravity dams are type VA. If you cannot find one in your county, try your state.

    3. Once you have found a gravity dam in the National Inventory of Dams' database, fill out you worksheet with the information about your dam. This dam is the subject of the rest of your WebQuest.

    4. Go to the section on Dams. Read through the section on the Societal Nature of dams. Answer the questions on your worksheet about the services dams provide.

    5. Read through the section on Opposition to dams and answer the questions on your worksheet about the problems of dams.

    6. In the section on Dam Types, go to Arch Dams. Here you will gather the first three tools to do a simulation of a arch dam. Fill out the questions on your worksheet as you move through the pages on Arch Dams.

    7. Move on to the section on Cracks. Read through the section on concrete. Answer the questions on your worksheet.

    8. Go to the section on the Science of cracks. Here you will find the two final tools to do a simulation of cracking in an arch dam. Answer the questions on your worksheet.

    9. Proceed to the Simulation section. Review the reasons for a simulation. Click the forward arrow and review the steps to a simulation. Be sure to watch the movies on how to do each step of the simulation. Then follow the forward arrow to the next page. Perform a simulation of the dam you have drawn on your worksheet.

    10. Did the crack grow? Why did that happen? Answer these questions on your worksheet and then post a message about your results on the bulletin board. Your message should report on the which cracks in your dam grew and why.

    11. You must now estimate the loss of life if your dam failed. Go to the US Census Bureau (#) to find the number of people in the town closest to your dam. Fill the answer in on your worksheet. Then move to the Scenarios section to use the loss of life estimation, again filling in the questions on your worksheet.

    12. Now you must consider what you have learned about cracking and dams. Dams provide many services but also cause many problems. Put your group's answer to both of the following questions on the bulletin board:

  • If a dam is cracked, how can you use computer simulations to help you figure out what to do about it? Post your answer under the heading "Using simulations" on the bulletin board.

  • If a dam provides people with power or drinking water, but it is also killing fish, do you think the dam should be removed so the fish will live? Post your answer under the heading "Social and Ecological Impacts of Dams" on the bulletin board.


  • Worksheet

    The five page worksheet is here and each page should be printed out and filled in as you go along.



    Conclusion

    In this WebQuest you have learned about the services dams provide, the impacts dams have on the environment, simulating cracking in a dam, and estimating the loss of life if the dam fails. These are all things that civil engineers must take into account when they are deciding if a dam should be built or repaired or taken down. The engineers must work together, as you did, to solve their problems and make their decision about a dam. You've just had a glimpse of what it's like to be an engineer!


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