News: Design Errors Add Delay and Cost To SR 520 Project

Does the Responsible Public Developer disclose design or construction defects to stakeholders?
Absolutely!
Timely and full disclosure engenders trust, and the sooner the issues are disclosed the sooner they can be remedied.
At Foster we work with our clients in the construction arena every day. We know that no project is immune from defects in potential design or workmanship. History is full of examples of problematic construction projects, going back to Hammurabi, who enacted the first building code in 1780 BC (with some rather strict penalties). 3,793 years later human error still impacts construction projects.
It’s no surprise, then, that costly design defects have been discovered on the pontoons that are a critical part of the $4.65 billion SR 520 project. The Washington State Department of Transportation (“WSDOT”) has taken responsibility for most of the problem, stating that significant responsibility for cracks in those pontoons lies with its own engineers and that the pontoons will require expensive corrective work.
WSDOT designed the pontoons for the 520 bridge on a fast track, using its in-house engineers rather than having its contractor (Kiewit) responsible for the design. Designing the pontoons was part of WSDOT's strategy to attract lower bids and to complete the floating section of the bridge by 2014. The winning bid to build the pontoons was $180 million less than WSDOT’s own estimate.
Inspections after post-tensioning the concrete pontoons revealed spalling and cracking. The cracks in the pontoons and water leakage reportedly resulted from time-saving actions taken by WSDOT engineers, who apparently did not carry out as many modeling tests as they might have, before the pontoons were built. Existing cracks on the pontoons havewidened because there is insufficient steel rebar used to keep tendons in place. In a WSDOT press release, outgoing Secretary of Transportation Paula Hammond stated: “The results of our internal review show that we did not follow standards of good practice to validate the pontoon design elements, and as an engineer, that is particularly frustrating.”
Here’s a link to WSDOT’s statement about the pontoon problem.
WSDOT has announced that its repair plan is to de-tension the steel tendons, remove the concrete, and add steel rebar reinforcement. Then new concrete will be poured and allowed to cure. The estimated cost to repair the pontoons is $100 million.
The good news for us is that in almost all significant public construction projects (like the SR 99 Bored Tunnel contract), the SR 520 contract included a $200 million contingency fund for impacts like design and construction defects. The bad news is that half of the contingency fund will be devoted to solving a single problem, while the project remains delayed.
WSDOT’s incoming director, the Governor, and other state leaders, are working together to address these issues. The parties will likely draw lessons from this latest setback and work collectively to maintain public confidence. Just like Hammurabi.






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