Initial results from the recent inspection revealed that a section of the Alaskan Way Viaduct has settled an additional one-quarter of an inch to a total of approximately 5 inches.

The settlement continues to occur in the same area between Columbia Street and Yesler Way. No new structural damage was caused by the additional settlement, such as widening cracks or development of new cracks.

"The viaduct is still safe for drivers. We are very concerned about the new settlement, but it does not come as a huge surprise," said Harvey Coffman, Washington State Department of Transportation bridge preservation engineer. "This one-block area of the viaduct has been settling incrementally since we began monitoring in 2002."

"We are moving ahead to make repairs to the viaduct between Columbia Street and Yesler Way this fall, and this news reinforces the urgency," said project director Ron Paananen. "These repairs are part of our overall plan to keep drivers safe on the viaduct, and to take down more than half of the viaduct by 2012."

This fall, the transportation agency will strengthen the foundations of the four columns that are settling in this area. The repair work, estimated to cost $5 million, is one part of six improvements planned to replace or repair more than half of the viaduct.

The foundation work is expected to take six months to complete, and no lane closures will be required on the viaduct. Repairs involve drilling a series of steel rods, called micropiles, deep into the ground into the stable soil surrounding the existing structural footings. These micropiles are each able to carry a 95-ton load and will make a wider and stronger column foundation, preventing further settlement in this area.

Transportation department crews conduct visual inspections every three months to monitor the viaduct's condition and keep drivers safe. Full inspections and closures are every six months, with the next scheduled for October.