Correction 6/4/2013: A previous version of this story had a typographical error. The bridge is scheduled to be closed June 5, not June 6.
King County plans to close an old bridge near Kent earlier than originally scheduled, officials said Monday.
The Alvord T. Bridge is both structurally deficient and functionally obsolete. It’s the first such closure since last month’s I-5 bridge collapse in Skagit County.
The bridge was built in 1914 and crosses the Green River. It’s a steel truss bridge like the I-5 one that collapsed.
Rick Brater, King County’s roads engineer, said the bridge was beyond fixing. “This is basically a narrow two-lane bridge built to 1914 standards that’s managed to last almost 100 years, which is great,” He said. “But now it’s at the end of its useful life.”
About 2,500 vehicles cross the bridge every day and the county plans to have alternate routes posted.
The bridge cannot be refurbished because it has problems in just about every component: from the pilings, to the bridge deck, to the steel overhead structure. In fact, just like the I-5 bridge that collapsed last month, the Alvord T. Bridge is considered to be fracture critical. Brater explained that it means the bridge is safe, unless something happens. “If something should cause a certain piece of the bridge to break, the bridge could then fall down,” he said.
That’s believed to be what caused the I-5 bridge to collapse last month: a truck hitting that bridge’s overhead girders.
King County has eight fracture critical bridges, including the Alvord T. Bridge. The bridge was originally scheduled to be closed June 28, but after the I-5 incident officials decided to move the date up to June 5 out of an abundance of caution. Brater said he doesn’t anticipate any more county bridge closures for the next several months.
King County is asking the state legislature for the ability to raise more money to help maintain roads and bridges. Officials say they expect to close 35 bridges over the next 25 years due to current budget shortfalls.