Virtual laboratory instructional video for the lesson "determination of soil density in the field." Geotechnical Engineering (CEG3011) course at the University of North Florida
Hey Ryan. Great job on the video. There are a few things I wanted to point out that are potential issues. When determining the Cone correction factor you need to do this procedure over the base plate, as you also need to account for the sand that is between the thickness of your base plate and cone. Second thing is you cannot manipulate, vibrate. rattle, or move in any way or you will affect the result of your density. Thirdly when you remove the soil from the test hole it needs to be placed in a moisture proof tared container so that you do not lose moisture and makes it easier for determining the mass for figuring out the wet density. Also worth mentioning is having holes drilled through your base plate so you can pin it to the ground so it will not move on you while excavating the hole. you may want to look into the proper procedure for filling the cone/container. Hope this helps and clears up and issues with determining the density of in place soils using sand cone method.
I am just wondering, as opposed to the sand cone test, or nuclear density, or the balloon/water test, why not just put a thin bin-liner in the hole (very loosely put in), and pour water until the meniscus of the water is just touching the top of the hole? You could then just pull out the plastic bag, measure the volume of water, and that's that. I can't imagine it would be any less accurate doing it that way than a sand cone test? Could you elaborate please Ryan. I can imagine that air pockets might form, but if digging out to ~4inches was done carefully to make a nice bowl shape, surely this would be very accurate at calculating the volume of the hole (+/- a fraction of a percent error) with no need for any equipment other than a thin bin liner, a flat edge (so it touched the water meniscus) and some scales. Thank you
That would work if you control for temperature of the water, because the density, and therefore volume, of water varies significantly with temperature.
