Tennessee’s highways rank the best in the nation according to Overdrive magazine’s annual survey of truck drivers. In keeping with those standards, the Tennessee Department of Transportation (TDOT) embarked on a long-term construction project designed to ease congestion at a well-known chokepoint – the I-40/I-240 interchange in east Memphis.
Designed by Buchart Horn Inc., the $25.7-million project was awarded to Britton Bridge Company, which began construction January 2001.
Amy Griffin, construction supervisor of TDOT reported, “Originally, there had been one project, but it was split into two separate projects. Project One is set for completion in October 2003, and will contain three levels of the four-level project. Project Two will begin just before January 2004, and should be completed by the end of 2006, at possibly a little over budget.
“Originally constructed in 1964, I-40 was to go through Memphis, while I-240 was to serve as a loop around the city. However, litigation halted I-40 west of the interchange, and it was never finished through Memphis,” she noted.
Constructed almost 40 years ago, this section of road was not designed to handle today’s traffic. “This factor has led to numerous accidents and fatalities that snarled travel for hours,” Griffin added.
To alleviate the growing average daily traffic (ADT) burden which is projected to easily double by the year 2015, the four-level interchange will be the first of its kind in West Tennessee. I-240 will be widened with additional lanes. Entrance and exit ramps at White Station Road will be relocated. Several ramps will be constructed including a new two-lane ramp, there will be adjustments to another two-lane ramp, and reconstruction of a one-lane ramp.
Summer Avenue also will be widened to three lanes in each direction, with turn lanes and bike paths. Three existing bridges will be widened, while three other bridges will be replaced, and two new bridges will be constructed. Twenty-four retaining walls will be installed, mostly at bridge abutments, Griffin explained.
“The fourth level ramp-bridge, the tallest of the structures at more than 70 ft. high, will be completed in Project Two,” she added. The state has not let Project Two as of yet.
Charles Scott, group manager of Britton Bridge Company, explained that Phase One, widening the various bridges and constructing the flyover bridge that goes from I-40 west to I-240 loop south, is currently underway.
“To accommodate the enormous tasks, we have two 100-ton Kobelco CK 1000s working right now. We have one 250-ton Link-Belt crane. We’re just now starting to set steel, and that piece of equipment has really made the work easy. We also have a 4300 Link-Belt trackhoe, a 3400 Link-Belt trackhoe and various Cat equipment,” he said.
“While we’ve had night shifts in the past, we’re currently working a 58-hour week, no Sundays. We’re now finishing switching traffic to the outside of the project, demolition on the inside, and constructing the inside lanes’ structures. After that, we do the asphalt overlay which should take us up to our target date for completion,” Scott explained.
Wayne Stokes, senior staff engineer of Buchart Horn, reported that there were design challenges and problems that have arisen during the past year.
“All bridge structures were designed for seismic conditions. With a third level flyover 1,500 ft. long, the foundations proved problematic. We had some difficult soil conditions at some of the piers. Part of the problem was that footings in some instances were rather large. We had a difficult time fitting the massive footings into the footprints that we had available. It was a tight fit,” he said.
Most of the footings are being built on 4-ft. (1.2 m) diameter drill shafts with increments of 30 ft. by 30 ft. (9 by 9 m), and 8 ft. (2.4 m) thick. Shoe-horning those large footings in between and adjacent to the traffic lanes was quite a task for the company.
“There’s not a lot of room to work out there to install these footing, to get enough stiffness on the piers. This had to be done while moving traffic around the site. There was some false work involved supporting the existing bridges so portions of these bridges could be demolished. Some of the main line 240 bridges are being built in phases in order to accommodate existing traffic,” Stokes noted.
Construction is almost ready to move into Phase Four. That’s when removal of an existing ramp, widening of bridge number 5, the final phase of bridge number 9, and new lanes on Summer Avenue will commence.
Phase Five, the final phase, will begin in October of this year, and will consist of the construction of the deck overlay of bridge number 5.
Transportation Commissioner Bruce Saltsman recognizes that cooperation between motorists and Britton Bridge Company’s construction procedures means the state of Tennessee’s highways may well retain their number one ranking.
“We aren’t just building roads, we are building better communities,” he said.
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