Contractor Finds Uplifting Solution to Low Set Bridge

Thu February 16, 2006 - Southeast Edition
Kerry Lynn Kirby

Alabama highway officials weren’t about to let a small bridge stand in the way of safety.

But rather than raze it, they raised it — approximately 2 ft. (0.6 m) to make way for a $4.69-million project designed to ease congestion and improve safety at the accident-plagued Interstate 10/Interstate 65 interchange.

Mobile Asphalt Co. of Mobile, AL, is the primary contractor on the job, which includes extending lanes on both interstates, changing the alignment on the ramps, making concrete barrier rails taller and thicker and improving lighting, according to Jay Palmer, district engineer of Alabama Department of Transportation in Mobile.

Contractors started on the job June 11, 2005.

But the project involved some tricky site preparation before their work got under way: a two-lane bridge spanning Interstate 10 on Riviere Du Chien Road had to be raised approximately 2 ft. to allow enough vertical clearance for a new lane on the interstate, Palmer said.

The three-span bridge was raised approximately 21 in. (53 cm) in 2-in. (5 cm) increments over approximately three weeks by state DOT forces using hydraulic jacks, he said.

“If you do it all at once, the bridge will break,” said Palmer, noting the bents had to be raised independently and the approaches constantly leveled.

Among the elements designed to make the interchange safer are some alignment changes on the ramps that will make for an easier transition for higher speeds, Palmer said.

The interchange’s original design was for a much lower speed than motorists really do on the ramps, despite posted speed limits, he said.

The project also includes 1.2 mi. of additional lanes, some on Interstate 10 and some on Interstate 65, which involves extending some lanes that currently merge into other lanes, he said.

Better lighting also will improve safety at the interchange, said Jimmy Loftin, vice president of operations of Mobile Asphalt Co.

The job entails widening and resurfacing of the roadway, replacing existing concrete barriers on the bridges, extending barrier rails in the curves on overpass bridges and extending culverts as well as installing new lighting, Loftin said.

Mobile Asphalt, which was the low bidder for the job, is doing all of the earthmoving and asphalt paving, Loftin said.

Subcontractors on the job are Peavy Construction Co. of Mobile, which is doing the culvert extensions and concrete barrier rails; Bagby and Russell Electric Co. of Mobile, which is putting in the new lights and wiring; Grady Ralls & Sons of Evergreen, AL, which is doing the grassing; and Ozark Striping Co. of Ozark and Mobile, AL, which is doing the striping.

Work will include approximately 50,000 cu. yds. (38,300 cu m) of total earthmoving, with the dirt primarily being moved in dump trucks, Loftin said.

The job called for approximately 18,000 tons (16,300 t) of asphalt, he said. And approximately 1,800 linear ft. (550 m) of new concrete safety barrier and 500 linear ft. (150 m) of new guard rail will be installed.

Originally, the job was expected to be finished by November 2005, Loftin said. But the hurricane season — particularly Hurricane Katrina — pushed back work due to rain and difficulty getting materials, and they’re now hoping for mid-April, he said.

Among the equipment on the job are two excavators, a Komatsu 200 and a Komatsu 300, a John Deere 650 dozer, a Caterpillar dozer, a Cat 140 motorgrader, Blaw-Knox and Ingersoll Rand pavers and a Blaw-Knox MC330 material transfer vehicle, Loftin said.

He said Mobile Asphalt owns all of the equipment, purchased from Cowin Equipment Co. in Mobile (paving equipment), Tractor & Equipment Co. in Mobile (Komatsus), Thompson Tractor Co. in Spanish Fort, AL, (Caterpillars) and Beard Equipment Co. in Mobile (John Deeres).

At this point, Loftin said, there are approximately 25 workers moving material and working on the project.

There’s been a single shift in the day, but a night shift for paving will be added within the next couple weeks, he said. Once they start placing asphalt, they’ll start closing lanes, most likely between 6 p.m. and 6 a.m., Loftin said.

Limits on lane closures are mandated by the state and included in the company’s contract, he said. Not only is it meant to minimize inconvenience to the public, but it also is necessary for the safety of the workers. CEG