Repair viaduct, don't replace with expensive tunnel
Mon, 01/18/2010
The viaduct will stand another sixty plus years by replacing the one section that is failing at Yesler Way.
Propaganda about extensive foundation problems has some merit: however, a prominent consulting civil engineer (Victor Gray) has publicly stated that those problems can be economically solved.
In the 1970s, a gasoline truck hit the east column of the lower road at Yesler. The resulting huge fire damaged the reinforced concrete.
I was amazed that this section of the viaduct was not replaced immediately. Reinforced concrete structures are susceptible to failure from fire damage.
Prior to construction in 1945 there was a 6+ earthquake; hence builders drove 80 to 100 foot concrete piles under each column foundation to withstand the possibility of the surface soil sliding caused by liquefaction in the area.
The viaduct structure is steel-reinforced concrete that withstands earthquake shearing of column supports and keeps the beams from separating from the columns.
The State proposes a two-mile long tunnel estimated at $4.5 billion ($450,000 per foot!) Citizens pay the cost overruns. Voters rejected a tunnel twice. Our State has budget problems in the billions.
I request the viaduct be repaired, retained and the tunnel proposal be eliminated.
Calvin F. Bannon
Retired Professional Electrical Engineer-Seattle City Light
The Boeing Co. Consulting Engineer
Seattle