Narrow bridges

Crews proceed with $32 million project to replace six bridges: CEG

To date, the project is just over a third complete. The contract has 510 working days. (photo by Caleb Tyler)

In southeast Alabama, crews are working on a $32 million project that will replace six functionally obsolete bridges along Interstate 85 at Exit 60.

The structures are being replaced due to their narrow width and age, with the Alabama Department of Transportation (ALDOT) overseeing the work.

“Bridges over Long Street, the Norfolk Southern Railroad and Alabama Highway 51 (Marvyn Parkway) will be replaced with modern bridge structures with full-width shoulders of approximately eight feet, for added safety and relief from congestion. traffic,” said ALDOT’s Southeast Region spokesperson. Brantley Kirk. “The acceleration lanes from exit 60 will also be extended to allow traffic to merge more safely with busy I-85.”

The project is funded with federal and state funds, including a $10.8 million grant that ALDOT received from the USDOT Competitive Highway Bridge Program.

“Alabama was one of 18 states to receive a USDOT Competitive Highway Bridge Program grant,” Kirk said. “ALDOT completed a thorough grant application that met the requirements of the USDOT selection criteria, including innovation, economic vitality support, and project readiness.”

To maximize safety and reduce the project’s impact on motorists, ALDOT is taking advantage of an innovative approach that will allow two lanes of traffic in either direction to remain open during construction. By using the existing median as a temporary traffic lane, each bridge can be replaced in its current location.

“By keeping two lanes of traffic open in each direction, it allows the traveling public the least amount of delay as possible when traveling through the area,” Kirk said.

Lane closures will be possible throughout the project and are authorized from Sunday to Thursday from 7:00 p.m. to 6:00 a.m.

Kirk noted that the stretch of road had an average daily traffic volume of around 51,000 in 2020.

“Crews are using concrete barrier rail, with assistance from the Alabama Law Enforcement Agency, with a reduced speed limit and restricted lane closures to help keep people working in the area safe,” said he declared.

ALDOT awarded the project to McInnis Construction LLC of Summerdale, Alabama. According to McInnis project manager Ty Tyler, his company is the perfect fit for the current project.

“The McInnis family has been in the bridge business for over 50 years,” he said. “During this period, our team has successfully completed more than 1,200 projects. High-traffic multi-phase construction has become an integral part of our business model, and we have intentionally prepared our employees to thrive in this environment.

Tyler said carrying out work in a very congested traffic area, both on the freeway and on the overpasses of Highway 51, is a major challenge, as well as demolishing bridges on the freeway and city ​​streets without detours or traffic stops for more than 15 minutes. Other concerns include construction and demolition on the railroad right-of-way, construction of new tracks and stormwater drainage into the existing median ditch, and meeting a set number of working days.

Construction began in April 2021 and continues apace. The work is divided into seven phases in total.

“Phase 1 consisted of installing all applicable traffic control devices and placing a temporary barrier rail to allow work in the median,” Tyler said, adding that Phase 2 work includes the construction of new bridges in the middle areas, the installation of the modified slot drain and storm drainage. and the construction of new tracks in the middle zone.

Currently, work is in phase 2, with crews preparing to turn traffic to begin phase 3. The middle portions of phase 2 of the new bridges have been completed. The crews were able to build the new A ramp out of order.

To date, the project is just over a third complete. The contract has 510 working days. Currently, the modified slot drain and CV4.5 inlets are being constructed in the median, along with the paving of the middle Long Street portion of the project.

“Our subcontractor, Chilton Contractors, is carrying out the work on site,” Tyler said. “They have earned a reputation for being the best in the business when it comes to median work along the highway. They do a great job of managing their work to alleviate the adverse conditions encountered while working in the median, or which amounts to a big gap.”

As for the creative method that will allow two lanes of two-way traffic to remain open during construction, “we’re seeing multi-phase style design being used more and more in Alabama,” Tyler said. “Limiting inconvenience to the general public has taken precedence. While this has its benefits, it also adds challenges and costs.”

The approach used allows motorists to feel the least impact on their daily routines.

“Obviously the cheapest and quickest thing to do would be to allow roads to be closed and detours to be put in place,” Tyler said. “It would alleviate constructability difficulties. However, the negative impact it would have on traffic flow and journey times would not be pleasant. There is a price to be paid for convenience.”

The excavation also presented obstacles.

“The middle zone brings its own challenges due to water drainage,” Tyler said. “ALDOT set up this crushed agricultural base to be used in lieu of borrowing in these areas where needed. This helped the schedule and allowed us to meet density requirements in these problem areas.”

The project has about 12,000 cu. yards. of unclassified excavation, 42,000 cu. yards. loan and 17,000 cu. yards. agricultural base configuration overwritten.

Tyler noted that, as with any project of this size, the teams ran into a few unexpected issues.

“One example was slotted mid-drain sheets that did not consider the alignment of the vertical curve of the existing pavement,” he said. “This error in the plans was not detected until approximately 700 feet of structure had been poured. ALDOT developed a repair procedure to modify and retain the 700 feet.”

The weather was also a factor.

“Rainfall negatively affected median construction to some extent,” he said. “Paving operations have been hampered for the past two weeks, that’s for sure.”

The acceleration lanes from exit 60 will be extended to allow traffic to merge more safely with I-85. Tyler said the new bridge structures will have the extra width to handle the new acceleration lane, which should significantly reduce the number of accidents.

The main remaining tasks include traffic changes and the demolition/construction of the remaining parts of the bridges.

Bridge equipment includes Link-Belt 298 HSL, Link-Belt 248 HSL, Kobelco CK850, Volvo L90 loader and Takeuchi TB2150 excavator. The main materials required on the jobsite include rebar, concrete, AASHTO beams and asphalt.

For teams at work, safety is a top priority. Traffic management and the dangers associated with it cannot be overstated.

“Finishing the job on time and on budget and making sure everyone gets home safely are our top concerns,” Tyler said.

An important step in the construction was to fix the 168 feet. Modified BT-74 beams on the bridge over the railway during phase 2.

“These are the longest AASHTO beams McInnis has ever installed,” he said.

Construction is expected to be complete by the second quarter of 2024. For crew members, days can be long as they juggle various tasks.

“The period between the completion of one phase and the transfer of traffic to the next phase seems to be the longest part of the job,” Tyler said. “It’s not, but that’s how it is. I guess it’s the anxiety of wanting to start building the bridges again.”

He added: “Ultimately, a person’s or company’s reputation will precede them, and it’s up to us to make sure that’s a good thing. As builders, we pride ourselves on knowing that we contribute to our communities, both physically and economically, with roads and bridges that make this big world a little bit smaller.” CEG