Constructing 2.5 miles of elevated structure in the heart of Downtown Birmingham in under 14 months was a task only a few thought possible.

But, in June 2017 Johnson Bros. Corporation (JBC) took on the challenge.  Last January, the old bridge was demolished and work to erect the new structure began. JBC not only met the aggressive March 21, 2020 deadline set by the Alabama Department of Transportation (ALDOT), the project was completed more than two months ahead of schedule. The bridge for westbound traffic opened on January 17 and eastbound traffic opened two days later.  

“What an exciting day this is … Thank you for getting this project done ahead of schedule,” said Alabama Gov. Kay Ivy at the ribbon cutting ceremony.

This design build project was the most complicated phase of the 59/20 Bridges program to design and construct. From the preconstruction planning to the well-orchestrated onsite coordination, the JBC Birmingham team knew this project’s success was instrumental for ALDOT and JBC’s parent company Southland Holdings.

JBC looked at this project from all angles early into the procurement process. Understanding the accelerated bridge construction applications available assisted JBC in providing ALDOT with the best solution to minimize the duration of time the interstate would be closed while constructing a bridge to exceed the requirements of the specifications. Team members from JBC traveled to Australia to visit precast facilities, providing the project management team hands-on experience in constructing and managing this uniquely designed precast facility. The team also traveled to the Middle East to see firsthand an innovative custom erecting system, which the team elected to use, becoming the first project in U.S. history to incorporate this system.

MEETING CHALLENGES HEAD ON

Some of the challenges JBC encountered included coordinating a full interstate closure for up to 14 months with limited right-of-way for construction traffic.  There were also numerous utility relocations and varying geotechnical conditions along the project alignment.  These challenges were addressed during the pre-planning phases of the project through active collaboration with all owner, engineering, and construction partners.

The old bridges were built more than 45 years ago and designed to accommodate 80,000 vehicles per day. Before they were torn down, about 160,000 vehicles were using the bridges daily. By 2035, this number is expected to increase to over 225,000 vehicles per day, according to ALDOT officials.  

“This was the most aggressive and complex construction schedule in ALDOT history,” said JBC Project Manager Mike Brown.               

WHY SEGMENTAL?

It was established early into the design phase of this project that a segmental bridge structure would be the best method of construction. The project also included traditional bridge construction components for approach ramps and structures.

Utilizing segmental construction, JBC decreased the closure duration while increasing segment lengths.  By increasing the segment length, JBC was able to produce fewer piers and segments, saving ALDOT time and funding. This construction method also reduced noise along the busy urban alignment and provided the city a more aesthetically pleasing bridge. Overall, JBC casted 2,316 segments and 42 piers in 17.5 months.

To meet the schedule and provide the highest quality project, JBC constructed a custom casting yard within proximity of the project. The lessons learned from Australia assisted the project team in designing a workflow on the site, which played an integral part in the overall success of the project.  

The casting yard consisted of 12 casting cells, which delivered an average of twenty segments per day to the construction site. Casting utilized approximately 100,800 cubic yards of concrete during production, which was produced onsite and over 22 million pounds of reinforced steel. That is enough steel to stretch 3,996 miles – the distance of a road trip from New York to Los Angeles, then back to Birmingham.  

With the pre-planning coordination between the project and the casting yard, an erection sequence plan was prepared and provided the team with a seamless cast sequencing plan to coincide with the erection headings and direction. This plan also cut down on the amount of recasting, which could have caused construction delays.

PROJECT LOGISTICS

From the fabrication facility to the multiple worksites – working 24-hour shifts at times – the management team was diligent in maintaining a safe worksite while providing the highest quality product. Safety is of the utmost importance on all JBC projects and is executed through daily work crew meetings, front-end safety planning, and an overarching “Protect My Family” foundational mentality. Because of each person’s dedication to safety, Johnson Bros.  Corporation achieved an exemplary safety performance on this project.       

The coordination on this project called for the JBC team to manage an average of 40+ subcontractors and subconsultants on the project daily, along with over 500 employees working directly for the company.  With the need for so many workers, JBC worked with the City of Birmingham to create a workforce training program at their precast facility.  This program trained individuals on various aspects of construction, from tying rebar to forming concrete.  This program was successful in growing the skilled workforce in Birmingham, giving hundreds of local citizens a long-term career path, while providing JBC with safe and highly productive crew members.   

Following the completion of the bridge’s program, ALDOT and the City of Birmingham will be building an urban recreation area under the CBD bridge named City Walk. The park will include multiple outdoor activity areas for the residents and visitors to the city. City officials hope the park will serve as a connector for the communities on either side of the bridge. With the elevated clearance of the new bridge and the innovative lighting system, JBC is pleased to be part of the urban revitalization of this area.    

To learn more about this project, please visit 

www.5920bridge.com