City Manager Fred Ramey told the council at its Tuesday meeting that the 200-foot-long sandstone block wall between Ridge Avenue and Craig Street has been monitored since 2017 after residents in that area reported shifting and bulging in the wall.
Ramey said an engineer from local firm The Lane Group started a monitoring survey of the wall along 37 points. By February 2018, the survey found up to 1.5 inches in some sections of the wall along with a bulge at one point and a tension crack forming gaps between some of the blocks. That discovery led to the city closing sections of Ridge along the base of the wall and Craig above the wall.
Most of the shifting happened after the winter of 2017-18, and heavy rainfall could have been responsible, Ramey said.
Since that closing, Ramey said, movement along the wall was minimal. The road closures could have lessened vibration and weight stress on the wall, he said, but another structural engineer examining the wall said he could not predict safety factors or wall stability without destructive testing of part of the wall.
The wall could be as much as a century old, Ramey said.
Ramey said two options for the wall would be to build a safety fence along the wall or to keep the street sections blocked while continuing to monitor it. Some utility lines also run along the bottom of the wall, he said.
Councilman Mark Caruso asked if Craig could be reopened while keeping Ridge closed to see what effects that would have on wall stability. Ramey said that could be done along with another survey of the wall after a month. Caruso said putting a weight limit on Craig could also help the situation.
Ramey said that reopening Craig and putting weight limit signs would need coordination with the Virginia Department of Transportation to meet state standards.