I had a short break where loose ground settled and pulled the inside joint connector (like the one in the picture) apart, the tile settled down and separated.  I asked for a connector at Rural King, and they came up with an outside connector, with the barbs hooking the outside corregations of the tile.  Since I had never seen one, and was leery about how it might work, I started to protest.  I didn't say anything, as I realized I could use the damaged inside connectors and the outside connector, and end up with a very solid joint.

I just finished this morning with that repair, and was surprised at how well it went together.  It took a little more time to get both connectors mated, but the resulting joint seems much stronger to me.  I always thought those snap-in connectors were weak, but was surprised at how hard they are to separate when making repairs.  I expect the double joint to be used here often when repairs are needed.  May be overkill, but sink-holes are not a good experience, and can be hard on equipment if they are covered in vegatation and not seen.

BTW, I used a slab of concrete under the repair to help bridge the joint.  Never did that before, anyone have any experience to show it helps any, or makes things worse?  I like the way it supports the connection.  I used one of the concrete gutter extensions that are rounded to carry water from the gutters of a house away from the foundation, seemed to cradle the pipe well.