Rendering of what old and new bridges will look like after completion of both projects.
Construction crews in Tennessee are preparing to replace an historic bridge that dates back to the 1920s. Built by the State Highway Department as part of the special toll bridge program, the Edward R. Talley Bridge in Hancock County is being retired due to significant deterioration. It currently remains open to the public, as teams work to complete a new structure by 2014.
“The new bridge will not resemble the Edward R. Talley Bridge, in that it will consist of modern materials such as steel beams and modern geometrics, used with updated construction methods to meet today’s standards,” stated Ray Henson, transportation project manager 2 with the Tennessee Department of Transportation (TDOT). “The existing bridge consists of two 10-foot travel lanes, with no shoulders, and is 420 feet in length. The new bridge consists of two 12-foot travel lanes, with approximately six-foot shoulders and will be 480 feet in length. Mussel details and freshwater fish details will be recessed on the inside face of the new bridge’s rails. This is intended to bring attention to the area’s unique water habitats in the Kyles Ford area.”
The outdated bridge pays tribute to Sgt. Talley, who served in the United States Army during World War I, and received the Medal of Honor for his heroic actions. Also known as the Kyles Ford Bridge, the current structure is one of only three such bridges still in existence. Built for about $110,000, the bridge sits over the Clinch River on State Route 70. Considered structurally deficient, the bridge averages roughly 680 vehicles per day, according to a TDOT traffic survey conducted in 2010.
“Although traffic counts seem low, the Edward R. Talley Bridge has served the community of Hancock and Hawkins Counties very well over the last 85 years,” Henson pointed out. “Over the last several years, bridge inspections have indicated an increased rate of deterioration due to the age of the structure and increased loads.”
According to Henson, in order to keep the existing bridge safe and open to traffic, several bridge repairs have taken place over the years.
“Bridge inspections have indicated the need to lower load limits to the point that school buses and some emergency vehicles were not to use the existing bridge. The bridge’s posted load limits coupled with a decade of permit application attempts to replace the aging structure gave the Department no other option other than attempt a major rehabilitation effort to the existing Edward R. Talley Bridge. A rehabilitation project would have given an additional 30-year life span to the piers coupled with the addition of repairs to the main bridge span. No functional improvements were possible due to the existing bridges geometrics and pier’s limited load capabilities.
Henson added, “Another downside to rehabbing the existing bridge was an 18-month bridge closure necessary to complete all major repairs. The bridge closure would require signing a detour route that would add approximately 40 to 50 minutes of additional travel time for many commuters.
According to Dale Dockery, general concrete superintendent of contractor Charles Blalock & Sons Inc., the project was delayed due to a redesign issue.
“One of the piers was closer to the water than shown in the plans and another was farther away so we’ve shifted the bridge by four feet, so that had to get approval. We’ve got a number of tasks to complete on this job, including clearing and building some access roads near the river. Then we will drill two six-foot diameter drill shafts, one over each side of the river, and install the piers for the new bridge. We have to put the roadway approaches in, build the abutments and set the structural steel.
Crews of ten, working ten-hour, five-day-a-week shifts will use a 275-ton (249 t) Terex crawler crane to set the structural steel across the river, as well as a 350-ton (299 t) Grove all-terrain hydraulic crane to erect the steel. Workers also will use a track-mounted cason drill to install the drill shafts, and will make use of concrete mixer trucks. Blaclock and Sons is also responsible for the concrete deck, installing rails and paving the roadway when the bridge is ready to open to traffic.
“We will then begin rehab work on the old bridge, which will serve as a monument. That will involve some deck repairs. We have to repaint the steel structure and remove the concrete deck from the steel structure and put up some protective fencing to keep people from trying to get up on the old bridge.”
The new bridge, which won’t include overhead steel trusses, is a sense of pride for Dockery and his team.
“It’s rewarding to be involved in a project like this, and you want to give it your best to please the public and TDOT,” Dockery said. “It’s an interesting job because you never really build two bridges that are alike. They may look the same, but there is something unique you find each time. There are variables with the foundation, and you never really know until you get there.”
The biggest challenge, stated Dockery, is dealing with environmental restrictions.
“We are not allowed to touch the water in any shape, form or fashion during construction because it’s such a sensitive area for all the mussels. There are all kinds of environmental issues involved, which means we can’t even get in a boat. If we were allowed to float barges, the installation of the beams would be much easier, because we wouldn’t have to use such high cranes.”
The Clinch River, in fact, is one of only two rivers that are considered ecologically intact headwaters of the Tennessee River system. The Clinch River is home to dozens of vulnerable animal species, including more than 30 varieties of rare freshwater mussels and 19 species of fish. Rare plants, mammals and birds also can be found in abundance along the river’s edge. In fact, the basin has been identified as the number-one hotspot in the United States for imperiled aquatic species.
In 1990, The Nature Conservancy targeted the watersheds of the Clinch and Powell rivers as part of the “Last Great Places” ecosystem conservation program.
Environmental concerns haven’t been the only issue for TDOT. Because of the urgency of the existing bridge’s condition, a public informational meeting was scheduled to inform the communities of the present condition of the Edward R. Talley Bridge and the immediate need to address the condition of the existing bridge. The year-and-a-half bridge closure was not received well by the community and locally elected officials.
Said Henson, “The meeting resulted in a contentious response from a large majority of those attending. Afterwards, elected officials and other leaders within the communities met with TDOT officials and outside agency representatives and formally presented their concerns about having to close the existing bridge for such a long period of time. The communities felt that no consideration was given to the needs of an already economically depressed area and that an 18-month closure of the existing bridge would devastate all who depend upon crossing the Clinch River at the Kyle’s Ford location.
“Immediately following this testimony, the TDOT Commissioner announced a proposal to replace the existing Edward R. Talley Bridge with a new bridge in a near- same location while keeping the existing bridge open to traffic.”
The Department later presented two projects, divided into Phase 1 and Phase 2. The first required a repair project with less involvement than the previously proposed rehab project to the existing bridge. This required the existing bridge to be closed for a period of roughly six weeks. After completion of all the repairs, the load limits were increased to accommodate school buses and emergency vehicles that previously could not use the bridge.
The repairs on the old bridge are expected to last three to five years. Henson says the existing bridge will remain open with current load limits posted during the construction of the new bridge.The existing bridge was closed to all traffic until the completion of the Phase 1 repair project. Necessary repairs to upgrade the current bridge from the five-ton weight limit have been completed, and the detour route eliminated. The current weight limits for the existing structure are now posted as 10-tons for two-axle vehicles and 18-tons for three-axle vehicles.
After completion of the new bridge and approaches, traffic will be turned onto it and the Edward R. Talley Bridge will be closed to vehicular traffic forever. The Phase 2 project includes plans to prepare the existing Edward R. Talley Bridge as an historic ruin.
The Department also will provide a parking and scenic viewing area for the public to use at the north end approach to the existing bridge in its final capacity.
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