Monday, July 25, 2011

An Insider’s Look under the US 2 Trestle

by guest blogger Brianna Ahron

Curious about the US 2 trestle rehab? You probably are if you take it to work every day, especially driving westbound before 5 a.m. or after 7:30 p.m. Here is an insider’s look under the trestle to see what’s really happening during nighttime closures.

The day before the first full nighttime closure of westbound US 2 trestle in Everett was our last chance to let drivers know about the project and what the upcoming closures would mean for their nighttime and early morning drives. It was also a big day for me: It was the day that I got to experience my first media event as a WSDOT communication intern. Not knowing what to expect, I followed cautiously behind my communication mentor. We arrived at the construction site about 9 a.m. and pulled into what looked like a gravel parking lot under the US 2 trestle. The only things in sight were a couple of houses, a long road, and a port-a-potty. This was not at all what I had expected for a media event. I expected to see something a little nicer – at least a portable for everyone to sit in.

After getting a feel for the scene, we put on our hard hats and orange vests, and got to work. We immediately began to set up for the 10 a.m. event. We put up an informational sign, got our media packets ready and then began the waiting game. First to show up on the scene at 10 a.m.  was project engineer Chad Brown, followed by several TV stations, including KOMO, KIRO, KING, and Q13.
Cracks in the US 2 Trestle

As TV stations arrived, Chad gave a brief description of the US 2 project to one station at a time. It was interesting to see the media interviewing process. The reporters made Chad repeat a statement over and over again in different situations, and took long segments of film of the surroundings called B-roll. The most amazing part of the filming and airing process for me was how quickly the media edits film in order to get it on the air. They started filming at 10 a.m. and aired the story just an hour or two later. It is amazing how quickly the camera crews work. I knew some of the process of film editing from touring a local news station, but I had never seen it happen right there on the truck and appear on television 30 minutes later.

After his briefing, Chad took the reporters and camera crews over to a section of the bridge that had not been repaired yet. He showed how severe some of the cracks in the girders had become and why this was a necessary project to extend the life of the bridge. Needless to say, camera crews and reporters were awestruck by the size of some of the cracks. I had seen cracks like that before when driving near bridges and not thought anything of them. Little did I know, the cracks can be potentially fatal for bridges, especially in an earthquake.

Tight quarters under the bridge

Then came the true behind-the-scenes part of the tour: Chad took the camera crews up to the work platforms under the bridge to explain the construction process. He described, in detail, what construction workers were doing to the nearly 850 girders: chip away the cracked and damaged concrete from the steel rods within the girders, place new cement over the exposed steel to reshape the girders, and finally apply carbon fiber mesh on the underside of all girders, damaged or not. The carbon fiber will help prevent any further cracking.

The workspace under the bridge is less than appealing for anyone taller than four feet. Even I, standing at 5’4’’ and probably the shortest person there, had to crouch down to move through the workspace. Some of the camera men had to test their agility while filming under the low girders and carrying their heavy cameras.

Being under the bridge gave reporters and camera crews an idea of exactly why full closures are necessary. Every time a car drove over the trestle, the bridge shook, which, in turn, shook me, the camera crews, Chad, and the cameras while we were on the work platform. We never felt we were in any danger from the bridge trembling, but it was much easier to see why the trestle needs to be closed  when crews place the concrete and carbon fiber. The mortar and fiber won’t set properly if there are any vibrations – and every time a vehicle passed, we were all trying to keep our balance.

Construction scene
Most drivers know that 65 nighttime closures are planned during weeknights this summer from 7:30 p.m. to 5 a.m., but have wondered why they need to last so long. Crews need the full nine-and-a-half hour closure time to finish necessary work each night and give the mortar and carbon fiber enough time to set properly.

Once the damaged concrete is chipped away from the girders and the new mortar is applied, it needs approximately two to three hours to set and reach a strength that allows cars to drive on the bridge again. The epoxy, a hardening and adhesive chemical, used to apply the carbon fiber mesh takes about four hours to reach the strength that cars can drive on the bridge. Crews need every minute of those nine-and-a-half hours each night to get the work done.

For more information about this project, visit the project website or to see more pictures throughout the construction project, visit our Flickr site.

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