Construction crews have been back at work this week at Clarks Bridge, where a replacement project had stalled for 45 days to ensure the support for a retaining wall had compacted and settled as needed. Work had been steadily moving along on the $8.7 million project to replace the 56-year-old Clarks Bridge, which spans the Chattahoochee River on Lake Lanier. But it had to stop where “no work could occur at the bridge,” said Teri Pope, district spokeswoman for the Georgia Department of Transportation.