# Building a Rock Tunnel



## StanleyAmes (Jan 3, 2008)

On the SJR&P we have 3 short tunnels that appear to be blasted out of solid rock. To build them we use the inverse of a cut and cover approach. 

1st the roadbed is built. Then an 8” rock wall is built on each side of the tunnel.

Next the tunnel is filled with dirt and the tunnel top curve is shaped in the dirt

For the top sides and roof of the tunnel we use thin rock and place it in tight.

Once complete dry mortar is used to fill the cracks and a concrete slab is pored over the tunnel top.

Once dry the dirt is removed it looks like a tunnel blasted out of the rock.

Photos of the latest tunnel are below

Stan Ames


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## Steve Stockham (Jan 2, 2008)

Now that is one very interesting method of making a tunnel! It looks great!! Thanks for sharing the pics.


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## GG (Jan 1, 2009)

Very neat. huh... I can use this concept !

Thanks for sharing. 

gg


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## John J (Dec 29, 2007)

that is a great idea. Why didn't I think of that 


The state of Ariozona is using about the same process to build overpasses for a new free way

They build a big mound of dirt. Then they put the over pas forms in place. After the concrete is cured The removed the dirt from under the forms and take the forms off The Mound of dirt becomes the aproach to the over pass


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## tom h (Jan 2, 2008)

Neat idea Stan, do you have more pics of front view?

tom h


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## GarryNCGRR (Jan 18, 2008)

I like it.....looks really good. Also very good timing for me, as I am wanting a short tunnel like that! I had an idea how I was going to do it, but like your way better. Now if I can only get it to work as well as you did







Thanks

Garry NCGRR


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## smcgill (Jan 2, 2008)

Stan 
I did it the old way.
Plastic tube then the ends!


























I did check for clearence!
That is a neat idea though.
I can't wait to come back and see the results first hand!
Sean


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## Del Tapparo (Jan 4, 2008)

(No more quick replies. They keep disappearing!)

Nice idea Stan. Great results.


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