In the wake of a multi-million dollar bridge design mistake, the Washington State Dept. of Transportation fired one engineer and demoted another.
Post-tensioning design flaws cracked the first four concrete pontoons built for the replacement of the world’s longest floating bridge in Seattle. And the fix will cost millions and potentially delay the $4.13 billion project. The issue was blamed on state bridge designers rushing the job to meet accelerated timelines, according to an independent report led by bridge expert John Reilly.
In early 2013, when the first four pontoons were inspected on Lake Washington and found deficient to last the 75-year lifespan, WSDOT officials said internal discipline would come, likely to two employees. It has.
Mike Lindblom, of the Seattle Times, reports that the state’s head of the Bridge and Structures Office, Jugesh Kapur, was terminated and another non-named employee was demoted, both in early April. No other disciplinary action is expected.
At the time of the problems, then-WSDOT head Paula Hammond said “schedule pressure … drove many poor decisions” throughout a process filled with communication deficiencies and confusion regarding responsibilities. In the end, “inappropriate approval for post-tensioning tangent location change” was to blame.
The Times says that Hammond said in February that failure to run models was a key shortcut.
While the pontoons were deemed structurally sound for the planned 75-year life-cycle of the bridge, the up to five cracks of .03 in wide on Pontoon W posed watertight issues that threatened its ability to last the duration of its life.
Construction by joint venture Kiewit-General was not blamed in the report, instead fully pointing the finger at the bridge’s design, one that was sped up to meet timelines put in place by then-governor Chris Gregoire and done in-house, instead of delegated to a contractor.
At 7,710 feet, the SR 520 floating bridge will cost about $954 million to replace, using 77 pontoons. Of that group, 54 are “flanker” pontoons, says Julie Meredith, SR 520 program director, that don’t necessitate post-tensioning. But the spine of the bridge will take 21 longitudinal pontoons and two cross pontoons, all requiring post-tensioning for increased load strength.
Meredith says she anticipates negotiations with the contractor on the cost for incorporating the new design elements into future pontoon construction will stretch until the end of the year and the cost for the in-water fixes is unknown. The total project, still over $1 billion short in actual funding, had a $250 million contingency built in. About $200 million of the contingency remains, but the tricky western extension from the floating bridge to Interstate 5 hasn’t commenced, including the need to design the Portage Bay bridge.
The original timetable called for the final pontoons to arrive to Lake Washington in spring 2014, for a December 2014 finish of the bridge. “It may all change,” says Meredith. “It is going to be a question of what are the opportunities to recover schedule and what will that cost? How is that cost born between state and contractor?”
Tim Newcomb is Engineering News-Record’s Pacific Northwest contributor. He has also written for TIME, Popular Mechanics, Popular Science and more. You can follow him on Twitter at @tdnewcomb or visit his website here.