New Sketches!

The above picture contains the original drawings of what we thought the rain maker system would look like as well as a brainstormed design for the toe wall. The toe wall design pictured above is a grid type design that gets its strength from its multiple square shapes and the screws that run  

through the diagonal of each rectangle. Each node on the corners of the square doubles as a joint. As a result, the shape can be adjusted to fit curvature and lengths of hills. This also means that the wall can be added onto if necessary. Once this design this design is put into the ground, it cannot be adjusted.

The above sketch contains images of the rainmaker system as it was in the last lab. It is comprised of a 2 layer plastic screen made taught through a wood and metal square. 2 sides of the square are made from metal and the other 2 sides are made from wood.The metal sides are parallel to each other and double as sliders so that the square can lengthen in to a rectangle. This also allows us to put additional fabrics in between the two screens to create a more realistic rain effect.  The fabrics we considered for this purpose are paper towel, weed block,  and cheese cloth. we also considered leaving the screens bare but this requires lifting it above the bin at a certain height.

Lastly on this page, there is a model of  our control test with limitations of this particular design.

This last page contains a few more designs that were thought of during the lab period. The first two are made of brick with the second requiring the cutting of said bricks to increase surface area and therefore increasing friction between the bricks. The third design consists of using a biodegradable material that will be layered together and weaved through several posts and placed into a thin trench around the hill.

Rain Simulation Testing

The design for the "Rain Simulation" altered again during our trip for materials at Home Depot. While there we found a screen that could be double layered and felt that it would work sufficiently as water "filter" to simulate rain instead of just pouring water. Here were a few of the methods we tested:

The Very Initial Design (Cheese Cloth as a Barrier)

Cheese cloth between the layers of screen.
Note: The entire screen was not covered in this test, but was later on.

As seen in the video, the cheese cloth did not give an even distribution of water as it fell. In other tests with cheese cloth it was too absorbent and did allow enough water to fall through at once.

Using Only the Screen

Screen purchased from Home Depot to use in rain simulation.

In our opinion this method worked better than the cheese cloth. While the water was still not as distributed as we would have liked, it offered a better solution. 

Using Weed Block

Originally we bought weed block to line the bins so the soil would not be directly on its plastic container. As the rain simulating testing continued we tried to see what other materials were available, and weed block was one. We decided to try it because we felt it was thick enough to keep the water from being a constant stream.

Weed block between the layers of screen.

                                      

The weed block was by far the material that distributed the water the best. There were still some larger streams of water, but relative to the other materials they were much smaller. Weed block was also the only material that showed improvement by seeing "drops" of water come off of the screen. We thought we might be able to adjust this by pouring the water from a greater height.

                                     

The screen at a higher point above the container did have more "drop-like" water effects. As of right now, the weed block will be the material to use between the layer of screens.

Issues/Problems

1. The screen tended to droop in the center which was also a cause of a water stream instead of droplets. This effect can be seen with all three test cases which is why it was not a fault with one in particular.
2. The method of pouring water was also not the best it could be. We are looking into a material that could sit on the outer layer of the screen initially. This outer layer would pool the water until removed. When removed, the simulated rain can fall in all places at once rather than directly under where we are pouring. 
3. The height of the screen should stay consistent, therefore a structure may be built to keep the screen at a designated distance from the top of the container. 

Soil Density/ Water Content Concern

The properties of soil can vary greatly depending on the water content, and if we don't account for that our data can be extremely erratic. I thought of a process to dry to soil post testing. We could lay it out on a large sheet of the weed block and apply pressure with some paper towels. Then we let it dry in the sun, and maybe finish it off with hair dryer. What do you guys think?

Weekend Update

On Sunday, April 10th, the group went down to Home Depot to get supplies for the project. With that, we can start testing the project and achieve results that will help us make the best project

Rain Simulation Design

Initial Rain Simulation Design:
The initial rain simulation design included wax paper and cheese cloth and a surface of wire screening over the control containment bin. After discussion, we realized cheese cloth was subject to puddling and the cells of the wire screening were far too large for rain simulation. With this design the "rainfall" would be more like a stream of water on the soil slope.

New Design 1:
The first new proposed idea we really liked for rain simulation was a 3-D printed grid model. The grid would have holes so small that once water was poured it would act more like rain drops. An issue we found with this was time. As it is currently Week 2 our control testing needs to be started and the drafting of this grid would need to be completed as well as the actual printing of it. We are still considering creating this grid for use later on in the term or to keep as a prototype. Check back frequently as the design will be posted once complete!

New Design 2:
We decided we may not need a 3-D printed grid, but rather could use any durable material to create the rain simulator. Once a material is chosen it can be sized to fit over our containment area and holes can be drilled into it. We have ruled out wood and corrugated plastic as these are water absorbent. Our other options include non corrugated plastic and metal. After looking at Home Depot online we found a few materials that may be ideal, but would like to visit the store to see them in person and gather other miscellaneous tools we may need throughout the term.

More Background Information

After attending class today and hearing feedback from our advisor, the group thought it would be a good idea to provide a deeper understanding of how our project will be carried out. The "Week 1 Update - Planning" gives a brief outline of our plans but I would like to extend on that with the following.

The Three-Step Process
The toe wall is a necessary measure to stop soil from sliding any further down an eroded "dune." However, over time a toe wall would become subject to buckling due to the forces and pressure sliding soil puts on it. Our biodegradable intra-soil grid will be the next step to alleviate these pressures. It will provide a more stable structure for the soil. Both the intra-soil grid and the toe wall are still only temporary measures to soil erosion. They are to be put in place in an "Emergency Situation" to allow time for a permanent solution to be derived or implanted. The third step to our process - an erosion control blanket - may be the permanent solution of choice. The blanket will not only cover the surface of the area to keep the soil in place but contain plant seeds. Once these seeds are grown the extensive root network can provide a natural stabilization structure. This plant network is the main motivation behind using a biodegradable grid - it does not need to be removed and will eventually be replaced by the natural source.

The Control Environment and Its Purpose
We plan on creating a "control environment" which shows the sliding and erosion of soil prior to any of the measures discussed above. This environment will be a man-made slope of soil at a certain friction angle. Then a rain simulator will be used to "create" erosion within our model (see "Rain Simulation Design" for more information). After the simulation is run, we plan on measuring the change in angle.

Once the three step process is fabricated it will be tested by running close to the same simulation. It will differ by also adding a load to the top of the slope because only using rain simulation would not be a true indicator of our toe wall's success against sliding soil. The "success" of our project can then be determined if the change in slope angle during testing has decreased from that of the control environment.

Side Notes

• Soil from various places will be used for testing (Delaware County, The Pine Barrens of New Jersey).
• Durable and cost efficient materials will be researched. The proper material may also depend on the origin of the soil.

Week 1 Update - Planning

Week 1 of our Emergency Soil Stabilizer project consisted of forming a solution for the issue of rapid soil erosion. The initial design is composed of an immediate toe wall followed by an underground grid and a surface blanket. The toe wall and underground grid are temporary measures to provide structural support before the surface blanket is applied. The underground grid will be biodegradable to eliminate the need for removal. The surface blanket will contain plant seeds to provide a more permanent solution, as these plants will grow roots that stabilize the soil.

This design is projected to be completed in a ten week period. Below is an outlined schedule on a week to week basis. This blog will be updated weekly with our progress.