Building Bridges

Introduction

Bridges have existed for over 2000 years and during that time bridges have crossed swift rivers, deep valleys, busy highways, and other structures. We encounter bridges almost daily. It seems that we cannot ride in any direction without crossing a bridge of some type, whether it is the insignificant concrete culvert or the mighty Golden Gate Bridge.
Structural engineers have been using their math and science skills to design and build bridges for years, from the simple tree across the river to the modern Sunshine Skyway Bridge in Tampa, Florida. You and a partner will assume the roles of structural engineers that specialize in bridges. You will examine beam, arch, and suspension bridges and the basic shapes that are used to build these bridges.

The Task

In this WebQuest you and a partner will examine different shapes and discover their strengths and weaknesses. Next, you will become an expert on the different types of bridges and their use. Finally, using your knowledge of shapes and bridge types, your team will design, build, and test your bridge for it's strength. Then, your team will analyze the bridge's test results and create a construction report for your bridge.

The Process

You'll begin with everyone in your group gaining some background information from the Building Bridges Resources. As you gain knowledge, you will assume the roles of structural engineer and designer. In order for your team to gain knowledge and experience its members will need to:

Examine different shapes for their strengths and weaknesses in the Shapes Lab.

Then examine the way that forces act upon an object in the Forces Lab.

Examine the different types of bridges and their distinct advantages and disadvantages.

After completing the above activities , try out your design skills with the interactive bridge building websites.

As a team, you should have discovered valuable information about shapes and forces, and how they affect Building Bridges. Now as group members come back with expertise gained by exploring the Bridge Building Resources. You must complete the Webquest(ion) as a group. Each of you will bring a different viewpoint back to the group; some of you will agree and others will disagree. Use any information, pictures, facts, opinions from the webpages you explored to support your ideas. Your viewpoint is important and should be part of your teams solution to the Webquest. Your team should develop a solution that everyone on the team can agree with and accept.

Completing the Task

    You and your teammates have learned a lot by completing you research. Now is the time to put your learning to task. You and your teammates will need to design a bridge that you believe will be successful.

    Your team will first have to create a full scale drawing of your bridge on graph paper and attach an explanation of your bridge's design (what design features have you used on you bridge and why).

Writing Guidelines: Each team member should write a paragraph that supports the team's design or a portion of the design. In your paragraph be specific, use details. For example, if your team designed an arch type bridge explain why your team feels that the arch type bridge is a better choice.

    Once your design is accepted by the master engineer (teacher), you may proceed with the construction of your bridge. Your completed bridge will be tested for its strength by weighting it down until the bridge reaches the "Point of Failure". Your bridge will receive a load rating by dividing its weight by its load factor (last successful weight held).

    You will be given 150 flat toothpicks, 25 cm. of string, and a supply of white glue with which to construct your bridge according to your drawing.

Your bridge may be either arch, beam, suspension, or cantilever.

Your bridge must match your drawing.

You may use glue for joining parts but may not be freely applied to surfaces to reinforce.

Minimum bridge length 28cm.

Minimum bridge clear width 5cm.

Minimum bridge clear height 4cm.

Conclusion

After your bridge is tested, you will need to create an engineering report using the writing guidelines listed above. You will need to discuss you design, its features and its flaws. How would you improve your bridge? Where did most of the bridges in class fail? How could they be improved? Did your bridge fail in the same way? What feature did the most successful bridges have? How does shape affect the strength of a bridge?

Remember to have fun and use your imagination!!

Home SVMS WebQuests

Last Revised Wednesday, October 27, 2004