Washington State Department of Transportation bridge inspection crews reported a small amount of settlement of the Alaskan Way Viaduct near Seneca Street. No structural damage or new cracks were found during last weekend’s semiannual inspection and closure.

New settlement in this area was approximately one-quarter of an inch, bringing total settlement near Seneca Street to 1 and 5/8 inches since the Nisqually earthquake in 2001. Tests of the fire detection and suppression systems in the Battery Street Tunnel were successful.

All sprinklers in the tunnel are functioning properly, and only a few of the heat detection devices need repairs, according to a release from the state.

Crews also measured existing cracks on the structure and completed maintenance work including removing loose concrete, repairing expansion joints and damaged bridge rails, cleaning the Battery Street Tunnel and re-painting lane markings the entire length of the viaduct.

“While the viaduct remains safe for drivers, we will continue our inspecting and monitoring of this vulnerable structure every three months,” said Paula Hammond, Washington Transportation Secretary. “This is exactly why we are moving forward with work on the south end of the viaduct and why we are moving forward with construction of a replacement tunnel in 2011.”

In April 2008, four column foundations between Columbia Street and Yesler Way were strengthened after the columns had settled approximately 5 and one-half inches since the 2001 Nisqually earthquake. One year later, the columns are more stable, and no new settlement was detected in this area.

State bridge engineers and inspectors monitor the viaduct every three months and conduct full inspections every six months, as has been done since 2001.