A little cavitation. . .

Way back last December I wrote a post about how our nice black rural mailbox got pushed over by a great big delivery truck that ended up in the ditch by our driveway.  The driver came back and fixed the mailbox the following weekend.

Well, as it turns out, the mailbox wasn’t the only casualty.  As Paul Harvey would have said, here’s “The rest of the story.”

It’s like this, in the last few weeks we noticed a hole along the side of our driveway.  I thought maybe it was a rabbit hole, or even made by a groundhog.

(It’s a little hard to see in the shadows, so I thought I’d point it out!)

I mentioned it to The Farmer one day, and he informed me that wasn’t made by an animal, it was cavitation.

Say what?

Well, when you live with a civil engineer type person, there are often strange terms popping up in the conversation.  The only cavies I knew anything about that might be ‘cavitating’ were guinea pigs, or the South American kind that looks a lot like rabbits.  I didn’t think any of those critters were out here on the farm running around and making such a big hole by the side of the road!

But it turned out that this hole was over the top of the concrete culvert running under our driveway.  And it also turns out that one of the definitions in use for “cavitation” means a hole made in the dirt by the suction of running water. 

In other words, the water running through culvert created a suction that pulled the dirt down through the hole in the pipe, and thereby making a hole in the dirt.  Cavitation.

Well, The Farmer decided to fix the problem this weekend.  He dug down where the cavitation was so he could expose the expected hole in the pipe.

And here’s where we get ‘the rest of the story.’

Turns out it wasn’t exactly a hole in the pipe that caused the problem.  Nope.  Instead of a hole, there was a joint in the pipe there that was broken because the section of pipe on the end had got pushed down.

And HOW did it get pushed down?

Oh yeah, that great big delivery truck that knocked down our mailbox!

You can see where the weight of the truck pushed down deep in the dirt, and it’s right over the end of the culvert.  So instead of a little hole in the pipe, this is what we found:

The weight of the truck obviously pushed down the end section of culvert and caused the joint to break.

Well, NO way we could push that joint back up into place, so The Farmer had to so some of his famous jury rigging. 

He got a couple of pieces of wire mesh to put over the top of the joint, then covered it with concrete.

Once the concrete dried, he shoveled the dirt back over the spot.  Now you can’t even tell where the problem was.

And there you have it, ‘The Rest of the Story,” and hopefully, no more cavitation!