Building the Test Slope

The idea of the test slope is to find a "control value." The initial angle of the slope will be measured. Then, a load will be applied and the rain simulation will be run. After this, the new angle will be measured to see how much soil "erodes" with none of our proposed methods in place yet. 

So far, two slopes have been built and tested with an applied load but not yet with the rain simulator, as we are in the process of finalizing this design. (It has been an ongoing task to optimize its performance). 

Slope 1

The first slope created can be seen in the picture below. 

After taking measurements of the slope length, the height of the soil, and the bottom leg an average angle of 42.89 degrees was found. After applying a load, none of the soil moved. We observed that we may have packed the slope more tightly than would naturally occur in nature. It is also important to note that in a natural environment a slope would be free on the edges. 

Slope 2

We packed the soil in the second slope more loosely than that of the first. 

We took the same measurements and redid our calculations. This time the slope angle was calculated to also be around 40 degrees, it was 42.40. This was not done intentionally. However after applying the same weight, noting happened to the slope.

Improvements to be Made

• Finalize the rain simulation technique to also use in testing.
• Line the two remaining sides of the plastic container to cause less sliding.
• Line the container with a material with greater friction.
• Test using different soil types - ones that may be dryer or pack loosely because these are the types of soil that erode more easily.

Rate of Rain Fall Test Proposition

We need to be able to simulate a set amount of rain fall for each test for consistency of data. A good range for our purposes should be between 1 and 2 inches/hour, but closer to 1 in/h would be better. 2 inch is the cusp of severe rain. To measure this I propose that we take a small beaker/test tube and place it in our rain test box. We run the rain simulation for 10 mins and measure the depth of the rain in the beaker. Then that value is multiplied by 6 (there are 6 intervals of 10 mins in 1 hour) which should give us the rainfall/hour. We should then run the test again to make sure that the data can be replicated.  

Goal of Week 4 Lab

For today's lab, we decided to focus on the planning aspects of the project and make sure that everything can work together and we have all the pieces. It'll also allow us more time to test the project and each aspect rather than wait for one to finish testing to start the next piece.