Sunday, June 26, 2016

Monterey County, California Bridges: Wildcat Creek Bridge

April 2013 (36.4977, -121.9360) Wildcat Creek Bridge
It took a while but we finally arrived at a closed spandrel arch bridge in Monterey County. The Wildcat Creek Bridge has two 57 ft long arch spans and it was built in 1933. It's also different from the other arch bridges because the Pacific Coast Highway is further inland, away from the coast, and the concrete is in much better condition. Also, this bridge has a 34 ft wide deck, which is 8 ft wider than all the other arch bridges that we've been studying.

Sunday, June 19, 2016

Monterey County, California Bridges: Rocky Creek Viaduct

July 2014 (36.3697. -121.9027) Rocky Creek Viaduct
The headlands and cliffs around Big Sur have eroded so rapidly that sections of the Pacific Coast Highway had to be converted into bridges. About 600 ft of roadway just south of the Bixby Creek Bridge was replaced in 2014 with the Rocky Creek Viaduct.
This project includes a soldier pile wall with timber lagging placed behind the existing soil nail wall. Large diameter shafts with steel casings support hammerhead bent caps and a precast girder superstructure.  The bottom of the shafts are socketed into rock. As the cliff continues to erode traffic will be unaffected on the bridge.
A similar project (the Cow Cliffs Viaduct) is being planned just north of the Big Creek Bridge. As erosion continues to remove the ground under the roadway much of the Pacific Coast Highway in Big Sur could eventually be supported by a continuous viaduct.

Sunday, June 12, 2016

Monterey County, California Bridges: Granite Canyon Bridge

(36.4356, -121.9191) Granite Canyon Bridge
Similar to the Garrapata Creek Bridge, the Granite Canyon Bridge is a 288 ft long bridge with a 127 ft long arch span that was built in 1931. Also like the previously mentioned bridge, it has a lot of concrete spalls due to the marine environment and requires continually maintenance. 
All of these arch bridges along Monterey County's coast were built to enhance the experience of viewing the ocean while driving. That's why all the bridges sport an open barrier rail. In fact, these barrier rails are so popular that Caltrans eventually designed a crash resistant barrier rail that maintained the same open aesthetic.

The Pacific Coast Highway requires a lot of work to keep open, especially during the winter when landslides frequently cover the highway. People want to visit the ocean on the west side of California and the mountains on the east side of California and it's Caltrans' job to provide access to them.

Sunday, June 5, 2016

Monterey County, California Bridges: Garrapata Creek Bridge

March 2011 (36.41738, -121.91381) Garrapata Creek Bridge

The Garrapata Creek Bridge is another open spandrel arch bridge on the California Coast built in the 1930's. It's 285 ft long with an 150 ft long arch span. This bridge (eligible for the National Register of Historic Places) has corroded rebar that is spalling off the concrete due to the corrosive environment.