The Sunnyvale Sun
News
Mary Avenue footbridge is on solid footing
By Cody Kraatz
Right now, crews are busy making sure the Mary Avenue Bicycle Footbridge is on good footing.
The stunning steel suspension bridge will span Interstate 280 in the coming months, with a tentative opening set for April 2009.
"We're getting the footings poured and working our way from south to north," said project engineer Darren Lindsey, who works for Golden State Bridge, on May 28.
He stood on the south side of the bridge, where his crew was assembling a rebar substructure and wooden walls to hold in the cement for a footing, which was poured starting the next day.
The footing has taken about three weeks. When that's completed, work will move to the north of the freeway.
Once they hardened, probably in early July, trucks will bring in the 90-foot steel towers that will support the bridge. The freeway will be closed in the vicinity of the southern footing where southbound Highway 85 comes into southbound 280.
Huge bolts roughly 3 inches in diameter will anchor the 65-ton towers, and soon after 107 tons of steel will work its way across. A temporary support structure in the middle of the freeway that is currently blocked off with concrete barriers will support it.
In August the 2-inch steel cables are expected to arrive. Forty-four of them will fan out from the towers towards the middle and bases of the bridge. That support allows it to span 325 feet of the eight-lane freeway with no supports.
The city of Cupertino, the lead agency for this project, decided in August 2007 to go with steel instead of concrete when the lowest bids for the project came in at double its estimate.
The $10.2 million bridge is funded primarily by the Valley Transportation Authority, with most of the rest coming from the city of Cupertino and some from the city of Sunnyvale.
The bridge will be 500 feet long and 16 feet wide with a pre-cast concrete panel deck, according to the Cupertino city website. The area at its bases will include about 12 acres of native landscaping, sound walls and bicycle trails.
For more information visit tiny.cc/bikebridge.