Preparing for growth

New I-12 interchange to alleviate traffic congestion

By Angelle Bergeron

For the past 15 to 20 years, residents of Denham Springs, La., have been waiting for a new Interstate-12 interchange that would alleviate traffic in the popular Baton Rouge bedroom community.

Since Hurricane Katrina precipitated a population explosion, the opening of the Juban Road Interchange by the end of this year will be even more welcome.

"The population has been growing for years and they've been trying to get an additional entrance to the interstate between Denham Springs and Walker, La.," said Clay Holloway, project engineer for Louisiana DOTD. "Right now, there's an overpass, but no interchange."

Denton-James Construction of Baton Rouge began work February 2005 on the $18.6 million contract to construct the interchange and re-align a 1-mi. stretch of Juban Road leading up to the interchange, said Roger Daughdrill, project manager. Denton-James is re-aligning Juban Road, which is Louisiana Hwy. 1026, 800 ft. west of its current location so the contractor can install the new intersection before the old overpass is removed. In addition to providing on- and off-ramps to I-12, the interchange will provide greater flow for LA 1026 because it will be four lanes instead of two.

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"Our target date is to be finished by September, which would put us ahead of DOTD's November finish date," Daughdrill said. Because DOTD suspended the contractor's work on some holidays to expedite the flow of traffic, the contract will likely be extended through the end of December, Holloway said. Currently, Denton-James has only completed 43% of the work although 53% of the time has elapsed, he added. With a $5,000 a day bonus/penalty, the contractor has plenty of incentive to beat the deadline.

"Getting the initial embankment surcharge in and letting it sit was the main objective and it just took a while to get it there," Daughdrill said. "We had a lot of wet weather last year." In order to achieve sufficient compression, Denton-James placed a 3-ft. surcharge atop the headers for the bridge and had to let it sit for 90 days.

Placing the surcharge to speed settlement is standard, but this was the first time the DOTD specifications also required the placement of vertical wick drains beneath the header on the embankment.

"They placed the wick drains down 42 ft. into the ground to make sure they could get all the water out," Holloway said. The wick drains extend about 500 ft. north and south of the bridge and about 20 ft. from the top of the embankment, he added.

By the end of March, Denton-James began placing girders for the overpass. "Although the traffic isn't too heavy on 1026, it is really heavy on I-12, so setting up the girders has to be done at night," Daughdrill said. The contractor is only allowed to stop traffic from 8 p.m. to 5 a.m. and only for 20 minutes at a time.

"We expect more problems as we try and set up the girders (in late March)," Daughdrill said. "We are only allowed to stop the traffic for 20 minutes at a time to set a girder and with heavier traffic it will take longer than normal to wait until traffic clears so we can set another one."

In order to move cranes onto the site, the contractor had to stop traffic for 15 or 20 minutes, and then it took from 30 minutes to an hour before the normal flow returned, Holloway said.

"Since the hurricane, it's been bad, but from 8 to 5 they should have enough to get the girders in."

The contractor is scheduling delivery of eight of the 100-ft.-long AASHTO Type IV girders to be delivered each night.

"We don't have a laydown area, so we've got to take them off the truck as they come in," Daughdrill said.

Each of the 82,000-pound girders must be loaded onto the truck in a special direction and delivered in appropriate placement order, said Max Williams, vice president of sales at Gulf Coast Pre-Stress, the Pass Christian, Miss., company producing the girders.

"The biggest challenge will be getting the types of trucks with enough axles to transport them," Williams said. "No one company keeps that many pieces of equipment because you just don't use them, so we're having to round them up."

Although Gulf Coast contracted with Denton-James to supply the girders in December 2004, the company was hard hit by Hurricane Katrina. An 18-ft. storm surge pushed through the yard, destroying all of the company's raw materials, some finished products and all of the shipping equipment, Williams said. The six trucks Gulf Coast did have are either being rebuilt or repaired. "All of our equipment went under water," Williams said. "Some were totally lost and some could be re-worked."

Still, the largest tax-paying company in Pass Christian managed to rally, shipping out its first finished product a week after the storm and pouring it first product on Sept. 30. Although Gulf Coast is still replacing equipment that was corroded by the saltwater, the company is working full speed to keep up with the backlog created by ongoing projects like Juban Road and reconstruction projects.

In addition to the 60, Type IV pre-stressed concrete pilings, Gulf Coast will be providing Denton-James with 149, 14-in. piles and 48, 18-in. piles.

Without question, the traffic is the biggest concern for the contractor, as well as any subs scheduling deliveries. It is likely to get worse before it gets better, especially when Denton-James ties in the on- and off-ramps towards the end of July or beginning of August.

"We are going to narrow the lanes and move them over to tie in the off- and on-ramps, but that will be one of the last phases of the job," Daughdrill said.