Mountain Extension - Official Work Thread

[James Patten]

Today (and yesterday and tomorrow) it is actually above freezing.

[Ed Lecuyer]

Yes, It was quite balmy in Sheepscot yesterday - I think it may have hit 40 degrees!

[John Kokas]

Nice pics Mike.  Looks like we have a few trees a wee bit to close to the centerline.  Any beavers looking for work?   

[Paul Uhland]

John...good one!
Great pics. I see fine evidence of progress--less woods, more stumps.
Given da weather, you guys should be either sainted by the Pope, or knighted by the Queen...maybe both!
What' s really great is that  Trout Brook Bridge Project Sitework HAS STARTED!!
In construction-speak, it's called Clearing and Grubbing.

[Mike Fox]

I know everyone thinks we are nuts, but this is work we have to do now, while the weather is cold. So far, no soil has been disturbed. Not sure what the rain will do to the snowpack tomorrow and Saturday, so our work may have to be scaled back if the snow goes away.

[John Kokas]

A lot of people think Mainer's are crazy for venturing out in the winter.  Having lived in Maine and far upstate NY, one understands the real meaning of "cabin fever" and there are times when -10 below is a lot more desirable than another day coop'ed up in the house!

[Philip Marshall]

I agree 100%, Mike. There is a reason loggers prefer to work in the winter months, especially on wet ground or ecologically sensitive sites. It's all about minimizing soil disturbance.

[Paul Uhland]

Didn't realize there has to be such minimized site disturbance. Also, your time constraint is so tight. Wow.
Go for it.

[Mike Fox]

After the warm weather and rain the last 2 days...

[John Kokas]

That's a whole lot of water!  Ice jam?

[Gordon Cook]

Looking at the pictures taken today I was wondering how our Trout Brook bridge and site plans match up against the conditions that you observed?
How extreme was this event compared to the worst case that is planned for? 
And did you check the previous work sites to see what they looked like?

[Mike Fox]

While the water level may be high, it is far from the projected flood plain. The estimated floodwater height, according to FEMA, is about a foot below the height of the grade. Look at the included drawing, the FEMA flood plain is the blue line just below the bridge.

[Bill Baskerville]

Wow guys, we are going to raise the top of the rails 3 feet 2 inches above the current ground height.  Subtract rail and ties and that is about 2 feet 6 inches to the bottom of the ties.  I had no idea that we would raise the track that much.  Not that I am complaining, that is just a lot of stone and gravel.

Impressive drawings by the way.  Did Ed do all those?

[Jason M Lamontagne]

The drawings were a combined effort of Christopher Marston of the NPS, Eric Schade and myself.  While Ed wasn’t involved in this one, he helped us greatly with the production of very professional maps and site plans (which is Ed’s cup of tea).

The stream profile seen in the drawing is from an actual profile survey performed by several of us this fall.  Note in particular the “normal high water line” as labeled on the drawing, then note how quickly the banks fair out away from the stream.  The normal high water marks on site, and at any stream which experiences flow like this, are very plain to discern- as their sharply eroded for a short vertical jump in the profile.

As you can see, the volume of water required to get above the high water mark goes very high very quickly.  This is why the high water mark is so eroded- high flows rarely make it above this mark.

I wasn’t on site yesterday but from Mike’s pictures it looks like the water level is right at the high water mark.  It does this regularly. 

The “floodplain” on the drawing is the FEMA 100 year floodplain.  Now you can see why such an event is only expected every 100 years or so.

The bridge piers are required to be 20% wider than the high water marks.  We have achieved 80%.

See ya
Jason

[Jason M Lamontagne]

The raising of the rail height is to get the bottom of the bridge at least 1’ above floodplain, a requirement.

The raising will be accomplished with the use of retaining wall blocks on each side of the roadbed fill approaching the bridge, as adding that much more fill material right near the stream is frowned upon.  It’s be a lot of fill, and moreover would widen the roadbed fill substantially.

We are currently studying an option which would allow us to lower the track height 18” from that shown, while maintaining our foot of clearance above floodplain.  If we can accomplish this, the retaining wall can be nearly eliminated (some will he needed right at the pile abutments).

See ya
Jason