Deep Highway culvert installation, fish pass

[AKSherpa]

We are looking at installing a deep(50') 10' diameter cmp fish pass culvert. Considering installing in 2 stages so we can keep 2 lanes of traffic and a bike path open. I am looking for ideas on how to temporarily shore up the excavation longitudinally along the centerline of the highway. I am working with a cut approx. 45 feet deep in Sandy gravel soils, with traffic loading along top of cut. Any tips would be greatly appreciated.

Thanks

 

[oldestguy]

As one thought I'd do a search for soil stabilization or chemical soil stabilization. One link that came up on Google. Cement injection may also be checked out. There seem to be quite a group of contractors out there. I once had a contractor who used cement injection for a tunneling a 6 ft. diam. culvert under an Interstate highway.

http://civilengineersforum.com/chemical-stabilization/

 

[cvg]

for the price (and risk) of shoring or grouting with cut and cover trench construction, you might just want to consider jacking and boring instead

 

[dicksewerrat]

Pipe ramming may be an option also. why does this have to be 10 foot diameter? Why now? Where are the fish going now?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[oldestguy]

Another thought, why one big pipe? Why not a few smaller ones easier to install via jacking.

 

[GeoPaveTraffic]

Oldestguy,

While I know nothing about this specific project, I've been told in the past that the fish like larger openings. So one large pipe is much more effective as a fish passage than several small pipes. As it was explained to me, the fish don't like tunnels, so a larger pipe is less "tunnel like" than small pipes.

Mike Lambert

 

[nkrigPE]

I would recommend installing this by boring/pipe jacking if at all possible. We have designed installations of 10'x10' box culverts over 40 deep and had them successfully installed on grade (0.12% slope) via pipe jacking on lengths of over 1000 feet.

This seems like it would be more preferable than open cutting in loose soils to that depth.