With the Highway 33 Bridge in Union County on standby and this week's announcement that the completion of the Henley Bridge in Knoxville will be postponed eight months, TDOT is dealing with delays on a couple of major bridge projects in East Tennessee.
The two bridge projects share a striking amount of similarities. Both projects cost more than $20 million. Both construction plans were done in-house by TDOT engineers. Both projects were stopped in the middle of construction because physical conditions were worse than anticipated. Both projects required major redesigns after construction started. Both will require a lot more time and money than originally planned.
In both cases, the contractor handling initial construction was affiliated with Britton Bridge, LLC.
One major difference is the Highway 33 Bridge is still standing and operational while a new wider bridge is constructed 40 feet away. Since construction started in 2009, several thousand drivers a day have steered through the cones and narrow lanes to cross Norris Lake.
The Highway 33 Bridge was originally built in 1936 and is not safe for heavy commercial traffic. The Tennessee Highway Patrol guards both sides of the bridge to ensure loads that are too wide will not attempt to cross.
Construction on the new bridge stopped last May because of unexpected problems with the original plans. Those plans called for underwater blasting to construct bridge pillars by Mountain States Contractors, LLC (which is affiliated with Britton Bridge, LLC).
TDOT said once contractors began working in the deep waters, they discovered an unexpected amount of instability in the rock foundation beneath the old bridge. The contractor expressed fear that blasting in such close proximity could put the existing bridge's foundation in danger.
"It was more of a problem than was anticipated obviously, which is why they decided to cancel that contract," said TDOT spokesperson Mark Nagi. "I think the big thing though, especially when you look at Union County,
is you do have the existing bridge that is there. So while that project
has been delayed, it isn't like people there have a lengthy detour of an
hour or so that would occur if we closed the bridge entirely."
TDOT cancelled the contract and redesigned the plans to call for drilling rather than blasting the pillar supports. TDOT will begin accepting rebids for completion of the project on February 15. Britton Bridge will not be bidding on the remainder of the project.
Nagi said the problems with both bridges could not be predicted prior to construction.
"With the Highway 33 Bridge issues, that's something they [the contractors] were not going to be able to discover until they
got down into the water and started doing the excavation work. As far
as Henley is concerned, they weren't going to be able to do anything
until they did the work on those piers, start chipping away, and then the problem became apparent."
The problems with both bridges may have been undetectable without physically peeling back the physical layers of concrete or rock. Nonetheless, both TDOT and Britton Bridge met the misfortune of two bridge projects hitting roadblocks for redesigns mid-stream.
Britton Bridge spokesperson John Van Mol told 10News the most relevant common thread for the Highway 33 Bridge and the Henley Bridge is the age of the structures.
"True enough that in these cases the designer was the same, TDOT, and the contractor happened to be the same, but the key similarity was 70 and 80-year-old bridges," wrote Van Mol. "With these kinds of projects, the risk is greater that one will find conditions that were unanticipated. And typically this happens after the job begins and is well under way."
TDOT said it hopes to resume construction on the Highway 33 Bridge this summer. The redesigned plans will add around 20 percent to the original price tag of $22.5 million.
"These are very important projects, very extensive projects and we're trying to get them completed as quickly as possible in as safe a manner as possible," said Nagi.