What is "In the top of the NE abutment of bridge #"?

[+Weather Wimps]

OK, thought I would try my first benchmark. Plugged in the coordinates, drove to near the location, was pleased there was a bike path, took it to within 20 feet of the mark, which was next to a newish looking automobile bridge surrounded by 5 feet tall weeds/grass/etc.

 

THEN I read the description again and noted that it said the marker is in the top of the NE abutment of the bridge. What in the heck is an abutment?? I didn't go pounding in the weeds as I didn't know what this meant.

 

Is it on top of the bridge where the traffic goes, or is it underneath? And what are the chances of the marker being there if this thing was last found in 1934 and the bridge is modern?

 

Thanks,

 

Bob

 

Cache Long and Prosper

[+rdw]

The abutment(sp?) is where the bridge starts/ends. It is where the roadway leaves the ground and goes onto the bridge. It is usually a substantial concrete wall. I found two markers within the last week that were on abutments.

 

And if I'm wrong, I'm sure survey tech will correct me soon enough.

 

rdw

 

Abutment --          |          |          V---------------------------------------------##########       |       |       /#####################      |       |      /#######################     |       |     /#########################    |       |    /###########################~~~~~~~~~~~~~~~/##############

[+cachew nut]

Function: noun

 

1 : the place at which abutting occurs

2 : the part of a structure (as an arch or a bridge) that directly receives thrust or pressure

[+raouljan]

a·but·ment Pronunciation Key (-btmnt)

n.

The act or process of abutting.

 

Something that abuts.

The point of contact of two abutting objects or parts.

 

The part of a structure that bears the weight or pressure of an arch.

---> A structure that supports the end of a bridge.

A structure that anchors the cables of a suspension bridge.

[+juanbob]

Ok, so if the abutment is the part that takes the weight of the bridge - I understand this part - then how could a benchmark be on the TOP of an abutment? Wouldn't the road be on top of it?? Don't recall the mark I was looking for when I saw 'mark in top of NE abutment', but I do remember not finding it since I was looking at the wing walls of the bridge. Hmmm.

 

Juanbob

[+juanbob]

Ok, so if the abutment is the part that takes the weight of the bridge - I understand this part - then how could a benchmark be on the TOP of an abutment? Wouldn't the road be on top of it?? Don't recall the mark I was looking for when I saw 'mark in top of NE abutment', but I do remember not finding it since I was looking at the wing walls of the bridge. Hmmm.

 

Juanbob

[+raouljan]

Think of the concrete bits that come off the ends of the bridge... one on each side, two at each end.. go to the NE corner.. I'll bet it is in the concrete.. on top

[+Weather Wimps]

Thanks for all the replies!! And the nice drawing. :-)

 

Those weeds were quite a bit taller than 5 ft too (well over my head). Anyway, I looked under the bridge, up where the road/pillars first leave the hill, along the ground/rocks there, even climbed under the bridge and tried to look up. Next went on top along the side of the bike path/sidewalk.

 

No luck. :-( I have a feeling that they widened the bridge and added the sidewalks on both sides since 1934 ;-) and in doing so possible destroyed the marker??

 

At least I know what the underside of a bridge looks like now. If anyone has any other suggestions I will try again, but I am probably going to write this one off.

 

Bob

 

Cache Long and Prosper

[+TeacherMatt]

Here are some pictures of benchmarks that were described as being on the abutment...

 

Hope this helps a little

 

http://www.geocaching.com/mark/details.asp?PID=hv3042

 

http://www.geocaching.com/mark/details.asp?PID=hv3043

 

http://www.geocaching.com/mark/details.asp?PID=hv3045

 

http://www.geocaching.com/mark/details.asp?PID=hv3100

[+Kewaneh & Shark]

I was out and about on Labor Day and found this benchmark, HR0917, on a bridge abutment. I took a few pics. Take a look at them along with TeacherMatt's pics.

 

http://www.geocaching.com/mark/details.asp?PID=HR0917

 

It is not uncommon to put benchmarks in bridge abutments, sometimes called the deck or headwall, as they are usually built VERY well - thick, heavy, and deep into the ground - and therefore less susceptable to motion.

 

Keep on Caching!

- Kewaneh

[+WaldenRun]

Things that can happen to 'abutment' disks:

 

1) The bridge gets 'modernized' and the abutments are extended vertically to support the addition of quardrails. The disk gets covered in concrete.

 

2) The bridge is replaced and widened and the disk ends up being covered by the new bridge.

 

3) A series of bridges over a set of local tracks were raised to allow car carriers to pass underneath. Again, the abutments had to be extended vertically and most of the disks were covered. One disk was far enough out on the abutment to survive, and I found another in the LOWER end of the abutment.

 

WR

 

"Why worry when you can obsess?"