Sand physics and digging?

I want to try and simulate sand and dirt physics similar to those of the "falling sand game" but also being able to place solid objects on top of them and being able to "dig" out the sand or dirt. How could I do something like this?

Also, would this be possible on a large like I made a large world this way?

Something like this?

http://thisissand.com/

You can probably do this in Construct 2 using solid objects something like this:

https://drive.google.com/file/d/0B-xiqK ... sp=sharing

Your digger object will need to be a solid object too, and you will probably have to do lots of optimizations to make it run smoothly.

yeah "thissand" is basicly what i'm trying to accomplish, but your demo has given me a few ideas where to start, thank you