Video: Alaskan Way Viaduct Demolition Begins

March 15, 2019

Kiewit has begun demolition on Seattle’s Alaskan Way Viaduct, removing the first section of the double-deck structure. According to an article in Construction & Demolition Recycling, crews have used boom-mounted shears and hammers to work on and remove sections of the viaducts edges and tucked-away sections.

Kiewit has developed a multi-step schedule for taking down the viaduct, with crews working at several locations at once. So far, they have removed 450 feet of the Columbia ramp, about 360 feet of the viaduct near Pike street, and 650 feet of bridge at the viaduct’s north end.

Kiewit first got to work on Pike Street, and made its way to Columbia Street and Yesler Way. First removing the top deck and then the lower deck, crews will work their way north along the waterfront.

During demolition, Kiewit fences off the immediate area and begins prep work and staging. Then, excavators with breakers remove the roadway deck. Shears then crush and remove the supporting girders and columns that hold up the deck. In some areas, crews saw cut sections to be removed by crane.

The project gained notoriety when the tunneling machine, nicknamed Bertha, broke down and had to be repaired in the tunnel. 

Source: Construction & Demolition Recycling