A Dam Bridge Post

hee hee. I love being an engineer and the "wit" that goes with it :-)

Akiko's husband (here after referred to as AH... I can't spell his name :-) works for the company that is building the Boulder Dam Bypass bridge. That's the reason Akiko and her family are here. The company does projects all over the world and she comes with him as she can. I don't remember where, but there was a country or 2 that the whole family couldn't go to because of civil unrest. AH had to go around with a body guard.

Anyway, Akiko has offered many times to take us out there and I finally got to go. She had to set up two separate times to get everyone in (Marcia and Angus still missed out) so this time it was just Arvid and me... and Akiko, AH and her 6 yr old son Ted. Poor Ted. This was all old hat for him. He was bored out of his gourd! He did tell me all about snakes and we also discussed heaven, his grandparents, middle names, finding treasures (like a nut and a piece of wire), and why the seat cover was not snakeskin (i tried to convince him, but he wasn't having it).

I marked the 2 places we got to go...

First, the Nevada side.
Here is AH talking to a Carpenter.

This whole construction reminds me of Lord Of the Rings. You know how there was supposed to be all this huge ancient construction around middle earth? That's what I think it looks like, broken down monuments of an ancient society.
Remember that carpenter? I was excited to watch him go out onto the arch. It was around 2pm so one shift had ended and the next one hadn't started. It's too hot in Nevada to work through the middle of the day. I thought it was so cool seeing the guy all decked out and climbing those ladders, but I wasn't about to go out there even though Akiko suggested I could :-). Arvid didn't seem that interested either.
Do you see him there at the side, climbing?
AH told us they were pouring lengths of about 25 feet each side on a 6 day schedule. When they first started they were working at a 45 degree angle and everyone was new at it so the cycle was more like 25-30 days between pours. He said they kept dropping things and having a really hard time. He also told us that the thickness of the boxes (they are hollow) were 1'-6" at the arch and only 12" for the towers. Can you imagine? Seems very small for such a massive structure. AH told us wind was the governing factor in design which is one of the reasons its so small. You can imagine how strong the wind can get channeled down through the canyon.

I thought this was pretty funny. No drugs.... be Safe!

And here is the stretcher.

On the Arizona side, we saw a couple of rebar cages set up and it looked like they were only using a #8 bars spaced around 12". I've specified #10's at 6" for a retaining wall before! Arvid asked about why they decided to do Cast-in-place rather than precast concrete. AH said that logistically it wouldn't work. I can't remember the details anymore and it makes me mad... I think I'll have to ask Arvid :-)

Here's the crew (my camera accidentally got put on a different setting for most of the trip so I have to use Arvid's Picture). Akiko, AH, Ted, and Me..
And I couldn't resist putting in this GQ picture of Arvid, even though most of u don't know him.
Look at those huge cranes in the back! They are used to take material out to the ends. Those are the things that fell a year ago and set everything back a year.

I wanted to show you the bottom of the big pylons, but my picture didn't turn out. These are just temporary until the arch is finished.
Essentially, right now the bridge is a suspension bridge, but when it is finished it will be an arch bridge. Those tall pylons have a pinned connection at the bridge (as opposed to a fixed connection). This way they can move around as work continues alternately on each side.
Akiko's husband said they try and keep things as even as possible and check the movement many times a day. That's why this is such a big job because they had to design the structure to withstand construction, not just the final loads as a finished product. For example, right now the concrete is experiencing tension from being suspended above the bridge but once it becomes a full arch it will all be under compression. That's the whole point of arches. AH said you could hear the concrete cracking under the stress when you are out there, especially as it expands and contracts with the changing of the temperature throughout the day. These cracks will close once the "keystone" (or in this case, "key concrete section" :-) is in place.

This is where the suspension cables are anchored. Everything in this picture is temporary, including the cranes in the background.

Here is the sidewalk that will eventually be along the road.
Here is the view they will get from the bridge (well.. at one side anyways :-)The plan is to get the arch done, then work on the roadway from the center out. The hard part will be attaching the columns to the arch.
(Picture courtesy of Akiko) I learned alot and it was way cool. Arvid told Akiko we should go out again when it get's closer to being done. I whole heartily agree!

*UPDATE* go here for more information on the bridge..