Crews in downtown Nashville, Tenn., are working on a $62 million bridge rehabilitation that will replace eight bridges when work is completed in 2016.
Crews in downtown Nashville, Tenn., are working on a $62 million bridge rehabilitation that will replace eight bridges when work is completed in 2016. Known as Fast Fix 8, the project calls for significant closures, resulting in construction being completed in months, instead of years.
“These bridges are prime examples of aging infrastructure, and they are long overdue for major work,” said John Schroer, Tennessee Department of Transportation (TDOT) commissioner. “By using accelerated construction methods, we will greatly reduce the time a project like this would normally take, and will ensure these bridges can continue safely carrying the some 140,000 vehicles that use this stretch of I-40 each day.”
Originally built in 1968, the bridges over Herman Street, Clinton Street, Jo Johnston Avenue and Charlotte Avenue have been in need of repair for a while, with chunks of concrete simply falling off in some cases. Patches and repairs are no longer an option.
Crews are using a process known as Accelerated Bridge Construction (ABC). The innovative approach allows workers to reconstruct the bridges without stretching out construction. The work has been carefully planned and choreographed, so that tasks can be carried out in the most efficient manner possible.
As part of the ongoing work, a portion of the downtown loop is closed to all traffic for 13 weekends between July 2015 and June 2016. During the scheduled closures, I-40 will be closed from the I-40/I-65 split west of downtown to the I-40/I-65 split south of downtown. The interstate detour remains the same. Detours on local streets will be dependent upon specific bridge work.
According to TDOT spokesperson Heather Jensen, “The department feels the work thus far has been a tremendous success. The weekend interstate closures are the biggest challenge with this project. Downtown Nashville is a destination spot, with numerous events drawing thousands of visitors every weekend. TDOT has worked diligently to prepare businesses, venues, and visitors for the closures, so they know what to expect and can plan accordingly.
“During the first two scheduled weekend closures, motorists were able to easily and safely navigate around the work zone, allowing contract crews to complete the work in the allotted time. We anticipate the same success with the remaining bridge work.”
Almost half a century old, the twin eastbound and westbound bridges that cross over Herman Street, Clinton Street, Jo Johnston Avenue and Charlotte Avenue have been showing advanced signs of deterioration. According to TDOT, they require near constant maintenance. The bridges are located along the I-40 corridor, which is the main east-west interstate route in the United States and a primary route through downtown Nashville. The ABC work requires the closure of a two-mile stretch of I-40; however, the bridges are less than one mile in total length.
The biggest challenges on the project are the time constraints of the weekend closures. Crews have 58 hours to demolish and rebuild each bridge. Without accelerated construction, a project of this magnitude would likely take years to complete. Extensive planning and minute-by-minute scheduling is required to ensure the work is completed on time, and the roadway opens to traffic on schedule.
The location of a CSX rail line within the project limits also has been a concern. Construction schedules had to be coordinated with rail schedules in order to replace the bridges over the rail line within the 58-hour windows.
Kiewit Construction of Memphis, which specializes in large bridge replacement projects, is serving as the general contractor.
“The first closures were a tremendous success for TDOT and Kiewit,” said Jensen. “Contract crews were able to complete the work in the allotted time, even ahead of schedule. That said, there’s always room for improvement. Following the first closure, tweaks were made to the plans to improve not only construction, but traffic control as well.”
Specific to construction, TDOT and Kiewit have done ABC projects in other areas with great success. ABC speeds up construction and repair of highways and bridges by allowing short-term, total road or bridge closures to allow crews the space to do their jobs and the ability to work around the clock. This dramatically reduces the time to complete a project and the long-term inconvenience to motorists.
“The trickiest part is scheduling out all the small items that have to be completed in the 58-hour time frame,” said Marc Rothwell, Kiewit project supervisor. “There are a lot of moving pieces, and we cannot afford to miss anything.”
Weather also has been a factor.
“The heat was rough this summer, but tents and cooling stations were set up to protect workers,” said Rothwell. “Due to the aggressive nature of the schedule, we worked through the rain, but wet weather conditions were limited.”
Walls are completed in most areas under the existing structures. The bridges over Jo Johnston Avenue (eastbound and westbound) were demolished and replaced during two weekend interstate closures in July and early August. The decks for bridges over Charlotte Avenue and Herman Street were built in the median of I-40 near the I-65 split, known as the “south yard.” These bridge pieces will be moved from the yard to the bridge locations during weekend interstate closures over the next two months.
Crews are currently coordinating crane access, as well as erection of cranes and self-propelled modular transporters, in order to move the bridge pieces being stored in the work yard to the site locations.
A total of 44,000 cu. yds. (33,640 cu m) of dirt has been moved on the project. Equipment being utilized includes several large cranes — up to 600 tons (544 t) — to move bridge materials, a robotic dozer for placing material under the bridges where head room is lost, belt placers to place the materials in the walls and self-propelled modular transporters to move heavy loads. Dozers, track hoes, backhoes and skid steers also are required.
Some of the main materials being used during construction include 90,000 tons (81,646.6 t) of rock, 6,000 cu. yds. (4,587 cu m) of concrete, 35,000 cu. yds. (26,759 cu m) of excavation and 44,000 sq. ft. (4,087.7 sq m) of walls.
Jensen also said there have not been any significant issues to disrupt construction.
“The TDOT and Kiewit team have worked together utilizing the CMGC model of construction to work through the process to keep the project on track.”
Work began on Fast Fix 8 in April 2015. The estimated completion date is June of next year.