Buried Bridges Elevate Fort Lauderdale Runway

Odebrecht became aware of Fudo and the MVT method from its work on Louisiana levee projects, says Mauricio Gonzalez, project executive.

Reducing noise and vibrations—a benefit of MVT over the traditional deep dynamic compaction method—was vital considering the proximity of residents, aircraft and a control tower, says Rodolfo Armenta, an Odebrecht project manager.

Crews vibrate the deeper layers of ground for 90 seconds, two times, using a 10 ft by 10 ft steel plate, says Murtha. "In between, there's a 7 ft by 7 ft plate that is vibrated for 60 seconds," he adds.

"The larger plate densifies soils at deeper elevations, and the smaller one gives us concentrated energy on the upper layers," says Armenta.

If the specified compaction isn't achieved, "we trench and then we tamp again," Gonzalez says.

Additionally, the team is preparing to address some 1,777,500 sq ft, out of a total 5.8 million sq ft, where compaction is needed for depths below 10 ft, due to more extensive pinnacle rock.

This spring crews will begin using a vibratory rod method, where a rod or H-beam attached to a motor is inserted approximately 12 ft deep at predetermined spacings, says Gonzalez.

The rod is then lifted up a few feet and the hole is partly filled with material. Then the rod goes back down, compacts that material, and the process repeats until the hole is fully backfilled, he says. All compaction work is slated for completion by the end of year. Paving crews could mobilize in July, laying the groundwork for the runway's opening next year.

Aileen Cho, ENR's senior transportation editor, is a native of Los Angeles and recovering New Yorker. She studied English and theater at Occidental College, where a reporter teaching the one existing journalism course encouraged her to apply for the LA Times Minority Editing Training Program. Her journalism training led to her first stories about transportation, working as a cub reporter with the Greenwich Time. Her work has appeared in the Los Angeles Times and New York Times. Many of her experiences with engineers and contractors have inspired material for her alternative theater productions way, way off Broadway. For ENR, Aileen has traveled the world, clambering over bridges in China, touring an airport in Abu Dhabi and descending into dark subway tunnels in New York City. She is a regular at transportation conferences, where she finds that airport and mass transit engineers really know how to have fun. Aileen is always eager to hop on another flight because there are so many interesting projects and people, and she gets tired of throwing her cats off her computer in her home office in Long Beach, California. She is a very conflicted Mets/Dodgers fan.

Scott Judy is Deputy Editor for Regions, and editor of ENR Southeast, one of Engineering News-Record's 10 Regional publications. His roughly 27 years as a construction journalist began with an 11-year stint covering Midwest construction projects. In 2000, Judy helped launch the publication now known as ENR Southeast. He often delves into controversial aspects of the construction industry such as bankruptcies and fatal accidents, and wishes he would never have to cover another accident but suspects that he might.