Washington State DOT Unveils Plans for Fixing Bridge Problem
The agency had announced in February that a design error caused cracks in giant concrete pontoons for the new State Route 520 floating bridge across Lake Washington.
The Washington State Department of Transportation has reached agreement with its contractors on the cost and plans for repairing four concrete pontoons and modifying four others that are part of the new State Route 520 floating bridge. It will be a costly fix, in money and time, of a problem WSDOT acknowledged in February 2013, when it disclosed a design error had resulted in cracks in the initial cycle of concrete pontoons. These had to be patched in order to meet the new bridge's 75-year design life.
An engineering firm specializing in the repair of concrete structures devised the plan, which has been endorsed by an expert review panel. "These repairs are important to ensure we are building a safe bridge that meets the needs of the traveling public and supports the regional transportation system for many years," said WSDOT Secretary Lynn Peterson. "We are committed to following the recommendations of the expert review panel and moving forward."
For the first change order, WSDOT will pay $48.8 million to floating bridge contractor Kiewit/General/Manson, to fix cracks in the first six pontoons that were built. A second change order costs $22.4 million and has been completed. Both of these will be paid from the SR 520 risk reserve as part of the $2.7 billion program budget.
Peterson said the bridge is now estimated to open to traffic in late 2015 or early 2016. The existing bridge will 50 years old this month; it is vulnerable to earthquakes and windstorms and must be replaced, according to the agency.