In Arkansas there are quite a few 'low water bridges'. Just cement across the river , but it has to be pretty thick to withstand the current during high water. These are on public roads.
That’s what I’m trying to figure out if it will work. I realize a large amount (thickness) of concrete will be necessary to create a mass heavy enough not to move. Along with rebar to hold it all together.
If it’s at existing grade and thick enough, maybe even sloped on the sides, I don’t think it would undermine. But I hate to figure out otherwise the hard way.
