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March 5, 2015

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Engineering feat makes swapping out bridges on I-15 a snap

Slide method — ‘kind of an art’ — makes its Nevada debut in Mesquite


Julie Duewel, NDOT photographer

Nevada Department of Transportation and it’s partners work Tuesday to demolish two bridges along Interstate 15 in Mesquite and slide new bridges into the space, Jan. 10, 2012.

Mesquite bridge slide

Using hydraulic jacks, metal beams and dish soap, engineers and construction works slide new bridges into place on Interstate 15 in Mesquite, Jan. 11, 2012. Launch slideshow »

New I-15 bridge slides into place

KSNV coverage of a section of Interstate 15 in Mesquite getting replacement bridges through a new method of transportation engineering, Jan. 10, 2012.

Two bridges on Interstate 15 in Mesquite were replaced Tuesday night within a couple of hours using hydraulic jacks, metal beams and Dawn dish soap in a process called accelerated bridge construction.

Engineers from around the U.S. joined the Nevada Department of Transportation and its partners to see the bridge slide.

“This is the first one Nevada’s done,” said Marty Strganac, the department’s resident engineer.

The bridge slide is part of the I-15 West Mesquite Interchange Project, an undertaking that will cost more than $14 million to improve connectivity on the interstate.

Traditional bridge construction could take well over a year, said Dallas Hammit, deputy state engineer for Arizona, who was at the construction site Tuesday to see his first live bridge slide.

Accelerated bridge construction uses new technology to cut down the time it takes to replace an old bridge, Strganac said. In Mesquite, new bridges were built on temporary platforms right next to the old I-15 bridges that were demolished.

“It’s kind of a perfect situation,” said Strganac, adding that there was enough space next to each existing bridge to build replacements and the interstate wasn’t shut down during the project.

Traffic moving in both directions was rerouted through on- and offramps during the bridge replacement, said Strganac, adding that motorists are expected to be able to travel on the new bridges by Thursday morning.

Travelers aren’t expected to notice much of a difference, Strganac said, as the replacement bridges — each with two lanes — look similar to the old bridges.

There are no engineering guides to bridge slides, Strganac said. “It’s kind of an art at this point.”

Hydraulic jacks were used to lift the new bridges up and ease them on Teflon rails lubricated with dish soap, Strganac said.

Each bridge slides about 5 feet at a time, Strganac said. Construction personnel overseeing the project are trained to watch for any problems during the careful procedure.

W.W. Clyde and Horrocks Engineers worked with NDOT, the Southern Nevada Regional Transportation Commission and Mesquite to design and build the bridges.

The design company is based in Utah, where more than six bridge slides have been done, Strganac said.

Engineers like Hammit were there to watch and learn about the new method.

“It’s definitely going to help the local town,” said Hammit, who said that Arizona might use bridge slides in future transportation projects.

The impact on Mesquite will be beneficial, according to NDOT. The agency estimates that residents and commuters will save $12.7 million in time and fuel costs.

Along with the new bridges the project also calls for construction of roundabouts near the highway interchange, improvements to on- and offramps and the widening of Falcon Ridge Parkway to increase access, safety and traffic flow.

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  1. They better be careful. They will probably be besieged by the "Occupy" crowd: Luddites who oppose modern techniques that better our lives - even theirs.

  2. lvfactless adds absolutely zero to all discussion he is involved in.

  3. Get people to work by doing Infastructure Work. These are the type of Government jobs the Right Wing like "lvfacts - NOT " oppose in their zeal to beat Obama and the Country getting out of this economic mess. What an Un-American crowd.

  4. Adding Roundabouts?? As if there were enough reasons to skip Mesquite, that will add another reason...

  5. Mr. Fink seems to be suffering from Freudian Projection. The far left isn't the crowd who routinely ignores science and technology.

  6. Seems like a good idea.

  7. Very great way to get the job done faster, but as the photo clearly shows, there is plenty of soil compaction, sub-base and paving that will have to take place before any traffic ever crosses the bridge, so it's not really a "24 hour job". I don't see that traffic will travel the new bridges as fast as the article states (2 days). The second bridge (top of photo) has not yet been demolished, which will have to take place so the supports for the new deck can be installed. At any rate, it's good to see that work is being done to shorten the construction time (and cost) of such a project.

  8. I have always felt, that no matter how many other shortcomings it might have (and there are a LOT!) California knew how to build roads faster than anyone. If Nevada continues like this I might have to change my opinion. The work on US95 is progressing nicely as well from what I see.