EDITORIAL: Should have babied it

Cracking under pressure costly on S.R. 520 job

Blog Entry April 01, 2013
Bill Wilson

Bill Wilson is the editorial director of ROADS & BRIDGES magazine and has been covering the industry since 1999. He has won seven Robert F. Boger Awards for editorial excellence, including three in 2011. He also was the creator of the Top 10, Contractor's Choice Awards and Recycling Awards platforms, as well as ROADS & BRIDGES Live.

Printer-friendly version

I’ve been greeted with a Hello Kitty too many times over the last few weeks, and it’s usually in the middle of the night.


My youngest, Declan, is carrying on the deep family tradition of asthma-related illnesses, and last month he was diagnosed with the early stages of viral pneumonia. We would put him down for bed at his normal time, and before midnight he would suffer through a cough attack more suitable for an 88-year-old in the latter stages of emphysema. A couple of times I was tempted to search the bottom of his crib for lung tissue. These hacking seizures would often result in Declan coming into our bed and either my wife or I stumbling down to our daughter’s lair.


Our 4-year-old, Ainsley, has a nice queen mattress, but apparently it has been filled with concrete. If I listen hard enough, I think I can hear her bedtime companion, Hello Kitty, moan in discomfort—and she’s made out of stuffing. I endure it, because, well, it’s better than having your sleep covered in toddler phlegm. Still, I wish I had the ability to float through the rest of the night. Unfortunately, even my dreams feel like I am strapped to pavement.


Lake Washington in Seattle has the opposite problem—its bed is too soft. So officials went with another floating bridge to replace the one currently carrying S.R. 520. For months, however, this baby has been coughing up cracks. The first appeared along with spalling on the inaugural set of pontoons after initial post-tensioning in May 2012. All four gigantic blocks were detensioned and repaired, but additional in-water inspections showed more cracks, some as long as 10 ft.


Two expert panels revealed issues with the design, which is supposed to last three-quarters of a century, and in the end Washington Transportation Secretary Paula Hammond said, “schedule pressure . . . drove many poor decisions” on a jobsite that lacked communication and was filled with confusion regarding responsibilities. The official charge was “inappropriate approval for post-tensioning tangent location change,” and the fix could add hundreds of millions of dollars on the initial bloated price tag of $4.13 billion.


When I did a story on the S.R. 520 bridge back in December 2011, project managers knew the schedule was worthy of a weekly tantrum or two. Fish migration restrictions and hard winters will do that. During my interview, John White, project director at WSDOT, said, “This has some unique challenges because if you have a one-month delay that has you missing a weather window it could turn into a three- or four-month hit that you have to recover from.”


In other words, make your project delivery date or you are going to wish you were forced to sleep with a viral-dripping 2-year-old.


According to a blue ribbon panel, “The pontoon design did not adequately consider the effects of the post-tensioning layout, plus thermal and shrinkage effects.”


WSDOT supposedly did its homework regarding the mix design, embarking on the ACME (Advanced Construction Methods and Engineering) project for the pontoon construction. The goal was to test a variety of mix designs, thermal control systems, vibration approaches and different types of materials for forming.


So it seems enough time was spent up front, but once the project launched everything took on a hell’s bells kind of approach due to tight windows in the schedule. The sad element here is the existing structure is not dying hard and fast. Sure, it has its issues, but it can still do the job. A project as big as this required that careful examination to carry over into the execution. However, it appears those in charge said, “Good-bye, precautions” one too many times. R&B

Overlay Init