Week 9: Information and Lab Procedure

Lab Date: May 29, 2014
Lab Occupations

• Lauren Kujawa, Researcher/Tester
• Tyler Wicker, Researcher/Tester
• Chris Gibson, Researcher/Tester
• Sal Realmuto, Researcher/Tester
• Gabe Markowitz, Researcher/ Tester

Lab Information and Procedure

• Much information was given in lab this week.  May 29 was the last day in the soil lab, and the group built the final design of the retaining wall.
• It was learned that 1 piece of paper will give a cover ratio of 1, while a half sheet of paper will have a cover ratio of 0.5, so on and so forth.
• The factor of safety (or degree success) of a retaining wall is measured by:

Max Weight (capacity)

___________________

Actual Load (200 lb)

• A factor of safety of 1 means that failure is pending.  A factor of safety around 1.2-1.5 is usually acceptable for engineering projects.  1.5 is recommended for larger scale projects.
• The wall was built, using extremely small layers, and 200 pounds of weights were stacked on top with no failure.
• Using 4 whole pieces of paper, 748 square inches of area will be covered with paper.  In our final design, paper was cut from the whole pieces, and 220 square inches less than 4 sheets of paper were used, meaning the total surface area of 528 square inches covered by paper.  
• One layer was cut, and the wall failed instantly, which was expected because of the short overlap length of the middle reinforcements. 

 Image 1: Image of the final retaining wall, with 200 pounds of weights on top.

Image 2: Picture of failure.  One layer cut caused this failure.

Post Lab

• The final presentation was prepared after lab, and the final paper was revised from the draft that was due in Week 7.