I have a concret porch that was added to my home. It is "L" shaped, 42 feet up one side of the house and 17 feet halfway up the other side. The slab was not "tied" to the house slab. Now it shifts. Is there any way to stablize it cheaply? I thought about digging a trench most of the way around the house about a foot deep and a foot wide, then driving 8 ft steel posts into it. Wrapping cable from post to post, then filling the whole thing with concrete. BUT, I have waterlines, sewer lines, phone lines, and on and on and on.