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Quake-resistant canyon bridge opens near Quincy, CA, USA

 
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PostPosted: Mon Jul 16, 2012 6:51 pm    Post subject: Quake-resistant canyon bridge opens near Quincy, CA, USA Reply with quote

Monday, Jul. 16, 2012
Quake-resistant canyon bridge to open today near Quincy

By Jane Braxton Little
Bee Correspondent
California Department of Transportation The 354-foot-long Spanish Creek Bridge is one of the longest conventionally reinforced concrete spans in the state. It replaces a bridge, built in 1932, that is being removed.

Read more here: http://www.sacbee.com/2012/07/16/4633045/quake-resistant-canyon-bridge.html#storylink=cpy

QUINCY An elegant double arch rises out of Spanish Creek canyon, lofting 160 feet above the stream.

At its apex, it supports a new $29 million bridge bearing traffic on state Highway 70 eight miles north of Quincy.

Most motorists will never see the arch, a graceful structure 8 feet square at the base. The arch, made of solid concrete, is embedded with more than 1 million pounds of rebar.
1M16BRIDGE1.JPG
California Department of Transportation - California Department of Transportation The 354-foot-long Spanish Creek Bridge is one of the longest conventionally reinforced concrete spans in the state. It replaces a bridge, built in 1932, that is being removed.

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But drivers and the general public will benefit from the safety during earthquakes and the bridge's sheer strength, a carrying capacity of 360,000 pounds that quadruples the capacity of the old bridge.

The new structure includes wide shoulders, and architects designed a see-through barrier railing that both is bicycle-friendly and makes snow removal easy, said David Clark, resident engineer for the California Department of Transportation.

The Spanish Creek Bridge will be dedicated at 11 a.m. today.

Building the bridge, designed to last 75 years, was a unique engineering challenge, Clark said. "It's so high above the canyon and the canyon walls are so steep," he said.

Launched in June 2010, the bridge is located in a nexus of engineering feats that include a Union Pacific Railroad tunnel 100 yards from the east end. Just beyond the tunnel, towering 200 feet over the canyon, is an iconic "wye" railroad trestle where the Union Pacific line goes south to Oakland and the Burlington Northern-Santa Fe line heads north.

Train traffic ran regularly throughout the two-year highway bridge construction, Clark said. But crews had a close call last October, when dirt moved down the mountainside near the railroad tunnel and toppled a Pacific Gas and Electric Co. power pole. To stabilize the mountainside, crews removed 16,000 yards of soil.

The landslide cut off electricity to local residents and forced traffic across the old bridge to one lane.

"That threw a monkey wrench into the works," Clark said.

But bridge construction continued and the project was eventually completed a year ahead of the original 2013 schedule. The construction work was done by C.C. Myers Inc. of Rancho Cordova.

The 354-foot arch span is one of the longest conventionally reinforced concrete spans in the state, said Clark. To supply the 6,000 cubic yards of concrete, the contractors approached White Cap Ready Mix, a family-owned company in Portola.

"We said we wanted high-performance concrete and lots of it," he said.

It was a challenge, said Dixie Higgins, co-owner of White Cap: "You don't get much of a chance to step up and make that kind of concrete. We're proud to be a part of this bridge."

Funded primarily through the federal American Recovery and Reinvestment Act of 2009, the new bridge replaces one built in 1932 during the Great Depression as a Works Progress Administration project. It connected Quincy, the Plumas County seat, to state Highway 70 through the Feather River Canyon.

Last week crews brought in a 350-ton crane to take down the 1932 bridge, which was eligible for the National Register of Historic Places. The deck and the original steel trusses will be completely removed.

For Clark, who has spent 25 months overseeing the Spanish Creek Bridge construction, the satisfactions go beyond the beauty of the arch and the public safety the bridge promises.

In addition to winning an award for being free of accidents, the project has been honored for the partnership formed between Caltrans and C.C. Myers.

"Every project has its own culture," said Clark. "The people participating bring their own values, which become part of the project."

For the Spanish Creek Bridge partners, this included a 9-year-old boy with a brain tumor. One of the Caltrans workers made a wish come true for Jedidiah Lusk of Quincy. He knew the boy loved to play with Tonka toys, so he arranged for him to experience the real deal. Before he died in January 2011, Jedidiah got to operate a 40-ton hydraulic excavator at the bridge construction site.

"It may not seem like that has anything to do with building a bridge, but it's part of the team that built this one," said Clark.

Jedidiah's parents are expected to be at the dedication ceremony today to cut the ribbon across the Spanish Creek Bridge.

Read more here: http://www.modbee.com/2012/07/16/2283283/quake-resistant-canyon-bridge.html#storylink=cpy
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