When the Bridge Builders of Alabama won the $1.035 million project bid to replace the 12th Avenue Bridge in Phenix City, they were soon outshined by another win: the lottery. The engineer on record called it quits when his wife won the lottery with tickets purchased out of state.
“The engineer on record, his wife hit the lottery and he pretty much quit on the job, and there were a lot of design issues that somebody had to answer,” Casey Corley, Secretary Treasurer of the Alabama Bridge Builders, told Roads & Bridges.
“It was very difficult for us to get those answered and redesigned,” Corley said. The whole redesign process added six months to the project. The Bridge Builders of Alabama, in conjunction with the city of Phenix and the Alabama Department of Transportation (ALDOT), had to work together to get the crumbling bridge replaced.
“Our contract is with ALDOT. The county was supposed to be doing the inspecting, but we had to go through the chain of command. So we sent the [design changes] to our ALDOT inspector, then they are sent up the chain, then back to the engineer on record. And we could never get any answer from him, because, like I said, he had pretty much quit and shut down [his] company. So then ALDOT and the county had to find somebody else to do the engineering design,” Corley said.
The 12th Avenue Bridge, which sits roughly 40 ft over Holland Creek, was in a state of advanced structural instability, so much so that the surrounding community could not even rely on the bridge to carry its school buses and emergency vehicles.
According to the Phenix City Engineering Department, it was the worst-conditioned bridge in the city—ALDOT gave it a sufficiency rating of only 2 out of 100.
A structural evaluation deemed the bridge basically unable of carrying its approximately 1,000 vpd as the deck of the bridge was in a state of advanced section loss, deterioration and spalling. The super- and substructures also were stricken with section loss, cracking and scour.
Built in 1940, the 12th Avenue Bridge was a single-lane steel-girder bridge. It was rated for four tons and consequently could not support the type of heavy traffic crucial to a community like Phenix City.
Under the plan set forth by the Phenix City Engineering Department, the new bridge would be a single-span precast concrete bridge with piers. The bridge also would expand from a single lane to two 14-ft lanes and a 5-ft pedestrian walkway on one side, an element not included in the original design of the bridge.
The city of Phenix provided $207,000, a 20% match, of the $1.035 million project budget, with the remainder coming from the federal government.
The bridge replacement timeline was slated to take four to five months, but the completion date, initially slated for 2015’s construction season, stretched to June 2016, due to a few unforeseen issues that arose during construction, the lottery effect notwithstanding.
Failing deck panels being demolished and removed.
Not according to plan
Crews went to work on the bridge replacement on Oct. 28, 2015, and though they were aware of the issues from the get-go, stalling at the chain of command communication level in order to address the design flaws was more impactful than they anticipated.
“We noticed [the flaws] when we bid the job, but it took six months to get answers,” Corley said.
A major redesign issue that needed to be addressed immediately was the length of the bridge; it was not long enough. Instead of lengthening the concrete precast bridge decks, the Bridge Builders of Alabama engineered a different course of action.
“They didn’t end up lengthening, they just added some more panels, one at the end, and left the old abutment in place. We normally remove all of the old bridge, but they wanted to leave it in place to keep from having to make the bridge longer,” Corley said.
In addition to the length of the bridge, crews had to be mindful of the underground water infrastructure system around the bridge.
“We have a sanitary sewer main that’s actually encased in the creek, and we had some issues with that; we had to do some relocation work there because there’s actually two pylons that are spanning that,“ Phenix City Public Works Director Angel Moore told Roads & Bridges.
The Phenix City Utilities Department was able to work around the issue by replacing the sanitary sewer with a ductile pipe to prevent any damage from occurring as the contractor drove piles next to the sewer. Moore said this work extended the project timeline by two to three weeks.
“Then we had some issues with one of our slopes, so we had to do some redesign on one of our abutments and end caps, and put in some additional piles,” Moore said.
A structural engineer redesigned the pylons on the north end of the bridge where the slope stability issues were encountered.
“There’s an existing abutment that we were keeping in place and it had an existing wingwall. The original plan showed us removing that wing wall or a portion of it and driving piles right through it. And once we got to looking at it, it’s such a sheer slope out there that we didn’t think we were going to be able to do it once we got into the [actual]construction,” Moore said.
The city of Phenix also had to purchase two pieces of property since the bridge is a little bit larger—measuring 102.4 ft long and 37 ft, 8 in. wide—than the original version and because the wing walls were encroaching on private property.
In order to complete the project, the bridge had to be closed down completely and traffic rerouted. At one point both 12th and 10th Avenue Bridges were closed down to traffic, causing more extensive route detours.
Drivers in the area were asked to use alternate routes, adjust arrival/departure times and observe work-zone speed limits.
Moore explained that working with federal funding left less flexibility for the city to determine the project schedule.
“We had one gentleman concerned with why we closed both [bridges] down at the same time, and it’s because we were able to receive some federal funding, and when you receive federal money you do it on their timeline,” Moore said.
Once ALDOT approved the crucial redesign needed and another engineering firm stepped in to vet the changes, the project was back on track.
Crews put together the bridge deck by placing the precast bridge deck units with a LinkBelt 128 motor crane. The 12th Avenue Bridge still hit the jackpot with the amount of work and coordination that was done to restore and upgrade it. Residents of Phenix City were once again able to traverse the bridge by car or foot in June.