Monday, April 14, 2014

Our plastic sand demonstrates mass wasting. A draft.

Mass wasting and other slope processes using Emriver plastic sand. from Steve Gough on Vimeo.

At LRRD we have notebooks full of "what ifs" for our models.  As I worked on other things last weekend I put together this little demonstration and checked one off the list.

The video speaks for itself.  I've always known our plastic media could be used to demonstrate hillslope processes, but this is the first time I've attempted to record it.

I'm a fluvial guy and not so well versed on slope stability outside of the situations I see in stream banks — and even those are usually handled by a geotechnical engineer on my team.

So I'd appreciate comments on this little demonstration and how we can improve and expand it.

I was surprised to see how well the "mudflow" demo worked, especially since my wetting method was very crude.  With slow, methodical saturation of the slope, I think we could make wonderful simulations of this process.

We will likely have some interns working here this summer, and this looks like a great project for one!

As noted in the video, the flickering you see is from one of the awesome skylights we installed — great for energy savings, but not too hot for time lapse lighting on a partly cloudy day!


matt kuchta said...

I swear, we must be sharing the same notebook - I've been meaning to do a slope stability video, too.

What about using a watering can or something to add rainfall to saturate the surface.

As far as I've seen, most slope failures tend to be a result of saturating soil, causing it to lose shear strength - and the lower specific gravity of the sand means it will lose shear strength sooner than real sand - handy for a quick lesson.

Steve Gough said...

Matt, we have used agricultural sprayers in the past for adding groundwater to the Em4s; works very well; we'll have to build a system. You can add water with as little kinetic energy as possible, and very evenly, and at a known rate.

Jeff Clark said...

Yeah, the grocery misters are good too. Need to make sure that there are no large drips or you'll simulate an entirely different process - hill slope diffusion. The possibilities are endless!