While fighting waves of bitter cold that have marked January, workers are taking early steps to build a new bridge on Ga. 284/Clarks Bridge Road at Lake Lanier.
Tree clearing and utility line relocation is taking place on Ga. 284 south of the project. And a crew north of the project, across from Clarks Bridge Park, spent last week assembling specialized drilling equipment.
Generally, progress has slowed “because (workers) have to take more breaks,” said Teri Pope, district spokeswoman for the Georgia Department of Transportation. “The guys have to get warm every hour or so when it’s 20, 30 degrees outside.”
And there has been plenty of chill and wet weather since the $8.7 million project started to gear up in late fall and early winter.
Temperatures are expected to plummet to the teens again this week, including barely surpassing the freezing mark on Tuesday and Wednesday, according to the National Weather Service forecast Sunday.
“Once we get into the pouring of concrete, there’s a temperature component to that,” Pope said. “We do have specialized mixes that dry faster, but the longer it takes concrete to dry, the stronger it is, so you don’t want to speed that up too much.
“It’s a continual dance between the weather and what part of the job you’re trying to do.”
So far, crews have built a temporary bridge that will be used to move equipment, materials and staff to a barge, or working platform, in Lake Lanier.
“Working in the lake preparing to drill for the new concrete support structures, or caissons, is very specialized,” DOT District Construction Engineer Harold Mull has said.
Twelve caissons — 5 1/2 to 6 1/2 feet in diameter — will be drilled down to hit bedrock, to depths of 100-110 feet, Pope said.
Once the caissons are secured, they will be connected by a horizontal structure.
“That top part will take the bridge beams ... and then it will start looking like the bridge you think it will,” Pope said.
Safety meetings are held every week.
“For the last three weeks, we’ve been talking about cold and how to make sure (workers) are OK out in it,” Pope said. “(Crews) need to know what the signs of frostbite and hypothermia are, and even making sure they don’t get dehydrated in the cold.”
So far, the weather hasn’t affected the project’s completion date, which is Dec. 31, 2015, Pope said.
The new bridge will feature two 12-foot vehicle lanes, as well as 4-foot bicycle lanes and 8-foot shoulders in each direction.
Overall, the new bridge will be 952 feet long, nearly 50 feet wide and have five columns in Lake Lanier. Bike lanes and sidewalks will run along Ga. 284 for 2,781 feet.
The current bridge, built in 1958, is 834 feet long and nearly 24 feet wide.
The new bridge will be built next to the existing bridge, so traffic can flow normally during construction.
Then, crews will build approaches to the structure and install a 63-foot pedestrian tunnel connecting Clarks Bridge Park and the Lake Lanier Rowing Club/Lanier Canoe and Kayak Club’s boathouse to the Olympic venue and boat ramps.
Once the new bridge, approaches and tunnel are in place, the old bridge will be torn down.