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The Effect of Various Levee Designs on the Ability to Withstand Water |
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 Researched by Billy H.
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The purpose of this experiment was to determine the effect of various levee designs on the ability of a levee to withstand water.
I became interested in this idea when I heard about the floods in New Orleans and I thought that engineers should design better levees
The information gained from this experiment could save many lives and millions of dollars for those who live near levees.
My hypothesis was that the levee constructed with walls at a 45-degree angle would withstand the longest time against the water.
I based my hypothesis on the shape that today’s levees are constructed and what I know about dirt compaction.
The constants in this study were:
• Material that levee was constructed on
• Moisture in material
• Soil used to construct levee
• Amount of water held behind levee
• General testing method
The manipulated variable was the shape of the levee.
The responding variable was the amount of time the levee was able to hold back the water.
To measure the responding variable, I used a stopwatch to time how long it took for the levee to fail.
QUANTITY ITEM DESCRIPTION
1 Bag of potting soil
1 Cloth for drying plastic tub
1 Plastic Tub
2 Wooden block (2.54 cm Tall)
1 Wooden block (at least one inch long)
1. Place .946 liters of potting soil in a line directly down the center of the laundry tub
2. Use three wooden blocks (approximately 1 cm X 13 cm X 5 cm) to compact potting soil into a specific cross-sectional shape. Push down firmly on soil many times with block until the shape is stable and strong. Each levee should have a length that crosses the entire tub and meets the tub walls tightly.
One group will have a rectangular cross-section about 5 cm tall and 7 cm wide with vertical walls.
One group will have a triangular cross-section also 5 cm tall and 7 cm wide at the base.
One group will have a trapezoidal cross-section also 5 cm tall and 7 cm wide at the base but with a flat top about 2.5 cm wide and 45° walls.
3. For the first three trials create trapezoidal levees only.
4. Pour .946 liters of water on one side of the tub and start the stopwatch
5. Observe levee
6. When levee fails (water leaks through) stop timing.
7. Record data
8. Clean tub out and dry well.
9. Redo steps 1-8 until all three levee shapes have been tested three times each.
10. Average results for each cross-sectional shape.
The original purpose of this experiment was to determine the effect of various levee designs on the ability of a levee to withstand water.
The results of the experiment were that the rectangular shaped levee lasted 85.3 seconds on average where as the 45° tabletop only lasted 41.67 seconds on average.
See the table and graph below
My original hypothesis was that the table top levee with walls at a 45° angle would have the ability to withstand the most force created by water.
The results indicate that this hypothesis should be rejected, because the rectangular shaped levee held back water the longest.
After thinking about the results of this experiment, I wonder if I were to conduct this experiment on a larger scale, with more materials and shapes, and different soils the data would be different.
If I were to conduct this project again I would conduct more trials and examine more variables such as different amounts of water, and different rates of compaction.
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Introduction As early as 500 B.C. humans had built levees to save their land. Most of the Netherlands territory ranges from below sea level to 66 feet above sea level. Levees have clearly saved most of this country from repeated flooding. As the world has seen in the New Orleans flood, levees must be constructed properly or the result may be catastrophic. Levee Levees are wide walls constructed along rivers to prevent flooding or to hold back water. Levees can be made of sand bags, stone cement or soil. Levees along the Mississippi River are made of hard packed earth. They can be more than 100 feet wide at the base, 30 feet tall, and 8 feet wide at the top. The underwater parts of levees on the Mississippi are protected by woven willow or concrete slabs to prevent the levee from eroding away. The tops and sides have Bermuda grass planted on them to bind the soil together. Levees are always watched carefully to assure no areas are broken by burrowing animals, etc. When water levels are dangerously high they will sometimes blast away and flood only certain, less populated areas. They will also direct waters into other rivers. History The first levee ever constructed in the U.S. was constructed in the 18th century. After that, other farmers began building them to protect their land. States around the Mississippi river formed commissions for organized levee construction. In 1879 the U.S. government formed the Mississippi River Commission to assist the states. The commission is under authority of the Army Corps of Engineers. They have built over 2,040 miles of levees. Netherlands The name Netherlands means “low lands”. Most of the Netherlands territory ranges from below sea level to 66 feet above. A large amount of it is either under lakes or under the North Sea. The greatest hydraulic engineering feat ever, moved all of the water and made the land useful. In the Netherlands, as early as 500 B.C. overpopulation forced people to move northwestern towards the sea. To prevent their land from flooding they built hills of sod or debris, on which they constructed their villages. These hills (called terps) were the easiest way to keep small areas dry. Terps were only defensive measures though; there was no guarantee that their land would stay dry forever. In the 13th century land reclamation began with the construction of dikes. The first dikes were attachments to the terps. Later much larger land masses were protected by dikes. The land areas that were reclaimed by use of dikes are called polders. In the 13th century approximately 135 square miles of land were reclaimed. By the end of the 20th century more than 2450 square miles more were reclaimed. In the 1920’s the largest polder-creating project started in Zuider Zee. Cornelius Lely designed this project, which lasted from 1927 to 1932. During this time a dam 19 miles long was constructed across Zuider Zee, which separated Zuider Zee and Wadden Zee. A large portion of Zuider Zee was to be reclaimed into 5 polders. The first polder was named the Wieringermeer. It was completed in 1930. Since then three more polders have been finished, and one more is still to come. The total polder area is about 506,500 acres. Other than the Netherlands there are many areas where cultivation has been made possible because of dikes. In Denmark and Germany, dikes protect low-lying areas. Also, there are large areas near the Vistula River in Poland, the Po in Italy, and Danube in Germany, that are protected by dikes. Conclusion Levees play a huge role in protecting land and people from floodwater. |
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“Dike and Levee”. ELibrary. Encyclopedia Britannica, inc. October 17, 2005 “Repair Improvements for the New Orleans Hurricane Protection System” December 2, 2005 http://www.hq.usace.army.mil/cepa/releases/Interagency_Eval.htm Douglas Wallace, Clifford Baumer, John Dwyer and Frank Hershey. "Flooding And It’s Effects on Trees’’. November 16, 2005, http://.na.fs.fed.us/spfo/pubs/n_resource/flood/levee.htm Herzog, Heidi. Professional Civil Engineer. Telephone interview. November 1, 2005 Mays, Larry. “Levee”. World Book Encylclopedia. 2002 |
I would like to thank the following people for helping make my project possible:
• My parents for helping me obtain my supplies and helping me with my experiment
• Mr. Newkirk for supplying me with the knowledge I needed for this experiment and helping me with my experimental design
• Heidi Herzog, Professional Civil Engineer, for giving me useful information that greatly affected my project
• Mrs. Viernes for helping me with my computer help and after school work
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