FG,
So is that a 5, 10, 25 or 50 pound bag of beans? What kind of bag are they in?

Some stores around here have beans in bags that are made of a very fiberous white cloth that is plastic coated and very tough, you might look for something like that to help in the strength dept. The larger, 50 pound, bags are often burlap and can rip a bit when over stressed. If all else fails you can always cook em up and eat them.