Sunday, June 13, 2010

Construction and Frost Heaves!

When we drove to Alaska in 1995 we encountered a lot of road construction along the way. At times we would have to wait for 30 minutes or more for the “Follow Me” truck to lead us through the maze of construction equipment. There were a couple of occasions in the construction zones where we were driving on roadbeds that consisted of baseball size rocks. Mom and Dad also came through this kind of construction when they visited us in 1996 they cracked the windshield, headlights and incurred much paint chipping from the flying gravel on their just about new Honda Accord. So we decided we would be prepared, both having been scouts and all that! Dick built a really substantial shield to protect our Jeep from the flying rocks. Well we encountered almost no road construction the entire trip and what little we did encounter consisted of nicely graded gravel roadbed that was actually better than the paved roads. And that leads me to tell you about frost heaves!

Frost heaves occur when a road is built over permafrost which is permanently frozen ground. When the surface is paved it causes the earth beneath the road bed to heat up, thus melting the permafrost turning it to a jello-like consistency. The melting causes the road bed to “heave” creating a highway that is much like a roller coaster with dips that can be as much as a foot. It heaves from side to side as well front to back. Imagine cruising along at 55 mph and hitting this, you will be AIRBORN! We just heard about several people who broke their tow bars between their motorhomes and tow vehicle because they were unaware of the seriousness of frost heaves. We thought the frost heaves were much worse on this trip than before and that is because the road is older now. Frost heaves are a way of life up here and engineers are still trying to devise a road construction method that will preserve the permafrost. We passed over several experimental sections of highway on our way north.

1 comment:

  1. It looks like you two are having a great time! Wish we were there!
    Bill & Sandra