coal bin question

I have a coal bin in my basement that has concrete walls (the foundation), but from the window where the coal chutes in to the bin is about 10 feet. I need to build a "hallway" I guess that the coal can chute into and spill out into the main bin. I was planning on nailing some 2x4's vertically to the floor joists and putting up 3/4" plywood for the walls. I don't know what to use for the bottom where the 2x4's rest on the concrete floor, what is to stop the walls from bowing out at the bottom and collapsing the whole thing?

Just run 2x4 flat across the floor and tie them in to your vertical ones with screws and use plywood for the floor make like a box with 2x4 screw the playwood to them use tapcons screws for 2x4 for the concrete basement wall run a few 2x4 across the top for some more support to keep the outside wall from bowing out that should do it hope that helps you out

Use Tapcon screws and attach the walls to the concrete floor. they are very easy to use and work well.

http://www.itwbuildex.com/tapcon.htm

Thanks gambler I could not remember the name of the screws I ran down the stairs to look at my box of them to get the name but you where quicker then i was

I used a ramset (powder charge nailer) with 3 1/2 nails to fasten my 2X4's to my floor on the open sides. If you have access to one it is much quicker and easier than tapcons.

duplicate post oops

thanks guys, the tapcon screws should do the trick.