D E T A R E T L C E E C J W C N PRO A SHO 8 X I O F I T T C S U A F ONSTR T O D T C E G D I BR S Y A S A B C GR
RTN N D PA ITH A M S , M E SHA
CAS E 9
AS EASY AS
TDOT Fast Fix 8 Accelerated Bridge Construction Project LOCATION
Nashville, Tennessee C L IENT
Tennessee Department of Transportation, Structures Division, Bridge Inspection and Repair Office SERVIC ES
Bridge Design Intelligent Transportation Systems (ITS) Lighting Design Roadway Design
Four pairs of mainline bridges spanning downtown streets and active railroad tracks were rehabilitated utilizing 10 of the 13 weekend closure dates.
onstructed in the late 1960s, the twin eastbound “The Department wanted to complete the project bridges that intersect Herman Street, Clinton within a compressed schedule to minimize the social and Street, Jo Johnston Avenue and Charlotte economic impacts to Nashville’s central business and Avenue in downtown Nashville were showing entertainment districts, which are continually generating advanced signs of deterioration. Though all of the struc- huge traffic demands on I-40. By using ABC versus a more tures exhibited some degree of deck traditional delivery method, it was estimated the failure, the Charlotte Avenue bridge project could be completed within a total of 13 experienced three major deck failure weekend full-closure periods instead of up to issues during the summer of 2013. This three years of reduced traffic lanes.” required the closure of multiple traffic Along with ABC, Construction Manager/ lanes and an emergency weekend closure General Contractor (CM/GC) project delivery was to replace two bays of the existing deck. selected for the effort. This involved GS&P, TDOT Recognizing these four pairs of bridges and general contractor Kiewit Infrastructure along I-40 required immediate attention, South Co. working together to find the most Tennessee Department of Transportation reasonable cost for the project as well as the optimum methods for (TDOT) selected GS&P as lead design “By using ABC versus a more completing the reconstruction of engineering firm for the $62 million traditional delivery method, it the various bridge elements. bridge rehabilitation project. The scope was estimated the project could of work included comprehensive site “We identified four to six potenbe completed within a total of investigation, structural analysis and tial solutions for rehabilitating design, preparation of detailed roadway each of the four pairs of bridges 13 weekend full-closure periods and bridge construction plans, technical assessing criteria such as costs, instead of up to three years of assistance and research, and detailed materials, constructability, life-cytraffic management plans. cle analysis, risk factors and traffic/ reduced traffic lanes.” “It’s not uncommon for bridges that railroad impacts,” explains senior were built half a century ago to expe- TED KNIAZEWYCZ, transportation engineer Larry rience functional failures,” says senior Ridlen. “This evaluation process SENIOR STRUCTURAL ENGINEER structural engineer Ted Kniazewycz. was an incredibly valuable tool in “In the case of the existing I-40 bridges on this project, ranking the various site-specific options and identifying all the decks were showing consistent issues with their which should move forward for further consideration. At performance. This prompted TDOT to realize that an the end of the day, material procurement played a pivotal Accelerated Bridge Construction [ABC] project had to be role in the selection of final options for each of the bridges executed to address these issues. in respect to the accelerated schedule.”
Structural steel superstructure units were used on four of the eight bridges. These units were fabricated off-site at the "Bridge Farm" in the median of I-40, then transported and installed during the weekend closure.
TDOT FA ST F IX 8 AC C EL ER ATED B RI D G E C O N STRU CTI O N PROJ ECT
NO TWO BRIDGES ALIKE With the evaluation factors considered for the four crossing sites, the selected construction method turned out to be unique for each location, with no two bridges requiring identical restoration solutions. “For the Herman Street/NWR overpass, we decided to replace the existing superstructure with steel-beam superstructure units,” says Kniazewycz. “For the Clinton Street/CSX crossing, we chose a superstructure replacement of two spans with prestressed concrete bridge elements and the elimination of four spans. For the Jo Johnston bridge, we selected a superstructure replacement of one span with prestressed concrete bridge elements and the elimina...the single-biggest tion of two spans. For the Charlotte Avenue overpass, we decided to project challenge was replace the entire bridge with a that each bridge had to be single-span steel structure. “I think the single-biggest projlooked at individually in ect challenge was that each bridge regard to how it was going had to be looked at individually in regard to how it was going to to be accomplished. be accomplished. For example, the two 600-ton capacity cranes used for the Charlotte Avenue bridge had to be brought in from Canada. The contractor had to determine when those cranes were available, and our team worked backward from that date to make sure everything came together from a schedule standpoint. On the whole, the contractor had to look at the project through a holistic lens regarding what it would take to make things happen in the field.”
Precast concrete bridge elements were used on six of the eight bridges as a means of accelerating the overall bridge construction timeline. These included prestressed box beams, full-depth deck panels, precast concrete end walls and precast approach slabs. All components were fabricated off-site and shipped to the location just prior to weekend installation.
Sixteen superstructure units, each weighing in excess of 200,000 pounds, were installed on the Herman Street bridge.
“Not only were the plans welldeveloped, but there was a lot of discussion prior to execution regarding what would happen during the weekend closures — especially that first weekend.” LARRY RIDLEN, SENIOR TRANSPORTATION ENGINEER
WORKING FOR THE WEEKEND To deliver the project in the anticipated 13-weekend period, GS&P employed numerous innovative engineering techniques on the four sets of bridges. Kniazewycz explains: “We utilized structural steel superstructure units on the Herman Street overpass that were longer, wider and heavier than any comparable project that had been completed to date. These units were designed to be fabricated off-site, transported, and then installed during a single weekend closure period. In designing the superstructure units, we paid particular attention to standardizing the construction details to reduce the risk of fabrication and fit-up issues, which can be both costly and time consuming. “Another method to accelerate the replacement of a bridge is to reduce the amount of bridge there is to replace. To achieve this, the team utilized span elimination on six of the eight bridges, which not only reduces the amount of bridge construction during a weekend, but also lessens the amount of maintenance required in the future.” Precast concrete bridge elements were also used on six of the eight bridges as a means of accelerating the overall bridge construction timeline. These included prestressed box beams, full-depth deck panels, precast concrete end walls and precast approach slabs. All components were fabricated off-site and shipped to the location just prior to weekend installation. “Careful planning before the weekend closures played an important role in the project’s success,” notes Ridlen. “Not only were the plans well-developed, but there was a lot of discussion prior to execution regarding what would happen during the weekend closures—especially that first weekend.”
“Deciding exactly when those closures would take place was also key,” adds Kniazewycz. “Major weekend events that would be negatively impacted by an interstate closure—such as the CMA Music Festival—were factored into the weekend closure decisions to minimize impacts to local residents. When a weekend was identified for construction, alerts were issued to the public as soon as, and as often as, possible regarding interstate closures and detours. We also analyzed traffic patterns and selected I-440 and state Route 840 as alternative routes around downtown Nashville so we could divert as much traffic away from the project site as possible.” Weekend planning and scheduling also included the coordination of multiple subcontractors, suppliers, labor and equipment. Detailed hourly schedules and hour-by-hour snapshots of the ongoing work were tools used to accomplish the weekend work within a 58-hour closure window. “Each weekend closure started out with bridge demolition, which was scheduled to be completed within a 12-hour period so reconstruction activities could begin,” says Kniazewycz. “At times, both cranes and excavators were used on a single overpass in order to have enough resources to remove the bridge in time. As the project moved through the various weekends of construction toward completion, the crews were able to meet, and in most instances, beat the project requirements to have the interstate open in time for Monday-morning rush hour.”
LOOKING OUT FOR THE ENVIRONMENT
The mix design was approved for use on the project
as TDOT Class X concrete, and will be available to be utilized on future ABC projects throughout the state. This special concrete composite can be batched from a plant and delivered by truck, which ultimately saved more than 36,000 concrete bags from the waste stream.
TDOT FA ST F IX 8 AC C EL ER ATED B RI D G E C O N STRU CTI O N PROJ ECT
Along with leading-edge engineering techniques, GS&P incorporated numerous environmentally conscious elements into the effort. “The project promoted the reuse of the steel beams and rebar from the existing bridges,” says Ridlen. “Additionally, the demolished concrete from slabs was used as supplemental fill materials, and the new bridge designs utilized weathering steel, which doesn’t require painting and is much better for the environment.” Most notably, GS&P—in partnership with TDOT, Kiewit, Irving Materials, Inc., and Middle Tennessee State University’s Concrete Industry Management Program—developed a high-strength, ready-mix-type concrete that reaches 4,000 pounds per square inch in just four hours. After that time, a bridge can be opened to traffic. “The mix design was approved for use on the project as TDOT Class X concrete, and will be available to be utilized on future ABC projects throughout the state,” says Ridlen. “This special concrete composite can be batched from a plant and delivered by truck, which ultimately saved more than 36,000 concrete bags from the waste stream.”
A FAST-PACED THREEDIMENSIONAL PUZZLE Completed seven months ahead of schedule and utilizing only 10 weekend closures as opposed to the allotted 13, the Fast Fix 8 Accelerated Bridge Construction project restored four sets of mainline I-40 bridges in downtown Nashville with minimal impact to the environment, local businesses and residents, and the traveling public. “In the end, four different pairs of bridges with four different rehabilitation solutions, along with an ABC approach, equaled a challenging, fastpaced three-dimensional puzzle,” says Kniazewycz. “Our success was supported by the hard work and seamless communication of all parties involved. I am most proud of our team’s ability to meet the aggressive schedule. We had 57 days to generate final design plans for the eight bridges in total. Not only was this completed in 57 days, but those days fell over the Thanksgiving and Christmas holidays.” “GS&P was totally committed to the success of the project and worked long hours designing and redesigning the bridge elements to meet the capabilities of the contractor as well as doing what was best for the project and owner,” says Wayne J. Seger, P.E., TDOT Structures Division Director. “The team’s professionalism and design expertise, along with their flexibility and cooperation, made the Fast Fix 8 project a huge success for TDOT and the people of Tennessee.”
TE A M
PIC Mark Holloran, p.e. PM / PP Ted A. Kniazewycz, p.e. PD Larry Ridlen, p.e.
Thomas J. Carr Ben Coles, eit
The team’s professionalism and design expertise, along with their flexibility and cooperation, made the Fast Fix 8 project a huge success for TDOT and the people of Tennessee.
WAYNE J. SEGER, P.E. TDOT STRUCTURES DIVISION DIRECTOR
Cody G. Crews, p.e., env sp Cynthia Frear Katherine Ham Mickey Hamilton III Jonathan D. Haycraft, p.e., cpesc, env sp Rodney C. Palmer Buddy Sherrill, Jr., cpesc Wes Stanton Mark H. Washing, p.e. Gary Young
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