State can't tame Copper River but still aims to reopen highway

For a few years, all was good on the Copper River Highway, the mostly gravel road that runs for about 50 miles from Cordova on an old railroad bed across the Copper River Delta to Childs Glacier. The famed Million Dollar Bridge, a wreck since the 1964 earthquake, was reopened in 2005. Then last summer, road engineers were forced to close one of the 11 bridges that cross delta channels. Natural changes in water flow through the delta threatened the bridge's foundations and made it unsafe.

Last week, Alaska Department of Transportation engineers visited Cordova to update locals on plans for a new bridge they aim to open by 2017. The engineering obstacles are enormous. Then there's the money: None of the estimated $25 million construction cost has been allocated, reports The Cordova Times.

"This bridge is just the most recent episode with the Copper River," said Elmer Marx, AKDOT bridge design engineer. "Can we tame the river like the Columbia or the Mississippi? Well, perhaps with enough money but I don't see that happening." ...

Engineers described a fascinating array of issues that they deal with from scour, to seismic concerns to equipment issues. One problem they have yet to solve is the construction trestle or platform that will be used. The existing bridge is unsafe and cannot be used as a construction platform, or for moving people, equipment or vehicles. So the first issue is how to destroy and remove the current Bridge 339. Then next issue is to determine what can be used as a construction platform. A barge is unlikely since it cannot get to the location. The flow and scour make a span-by-span construction approach unlikely. One possibility is a flexible floating base.

Read more at The Cordova Times.