When the 2001 Nisqually earthquake shook up Washington's State Capitol building in Olympia, citizens across the state felt the vibrations, at least figuratively. With a tenant list that reads like a Who's Who of state politics, the Capitol -- also known as the Legislative Building -- is perhaps the state's most visible and symbolic public structure.
Although the earthquake delivered a punch of urgency, plans to update the building have been in the works since at least 1998. The state had selected M.A. Mortenson Company for the rehabilitation project, and company representatives were at the Capitol to sign the contract on Feb. 28, 2001 -- the day of the earthquake. They joined with state engineers immediately to survey the damage and signed on to do the emergency repairs and mitigation work to make the building stable and safe for occupancy until the rehabilitation could begin. All of the building's tenants moved out to temporary quarters during the spring of 2002, and the state Office of General Administration (GA) turned the building over to Mortenson in June of that year.
Ironically, the Nisqually quake actually facilitated the rehabilitation project, according to GA officials. Before 2001, plans called for the project to take place in phases over nearly six years, primarily due to the tenants' resistance to vacating the building during construction. After the earthquake forced everyone out in a matter of minutes, the planning committee convinced those involved that vacating the building not only was possible but would reduce construction time by almost half.
Phase One, including earthquake repair and seismic upgrades, concluded last May, coming in on schedule and under budget. Much of that work focused on the building's upper levels, the dome and colonnade that surround the rotunda.
"During the earthquake, the column tops separated and the freestanding Corinthian columns started to fall away from the building," Mortenson's construction superintendent, Neal Schaefer, explains. "On the east side, they fell as much as five inches. And they really only stopped when they hit one of the petals on the design. That kept them from literally falling off the building."
The huge masonry exterior dome -- all 50 million pounds of it -- also shifted in the quake by as much as three-quarters of an inch. The dome and the columns essentially were held in place by gravity, leaving them vulnerable to the rolling and shaking of seismic events. The work done in Phase One repaired much of the earthquake damage and reinforced the structural elements to withstand future shocks.
"From the ring beam -- the round slab at the base of the columns -- all of those vertical elements were basically stacked one on the other," Schaefer explains. "They were not affixed, not bolted. Now, we have tied all those vertical elements together."
Starting about 12 feet above the columns, workers drilled a four-inch core out of the center of each column, then inserted reinforcing steel and injected concrete. Metal pins and bolts tie the columns to the ring beam at the bottom and to the dome structure at the top.
"Actually, there are three domes," Schaefer explains. "The inner dome [visible from within the rotunda], the outer masonry dome, and a third one called the conical dome that's between the inner and the outer. The conical dome is a structural element; it supports the lantern [on top of the outer dome]. There's about 60 to 65 feet between the top of the inner dome and the top of the outer dome."
More than 60 tons of reinforcing steel were added to the dome and colonnade structures, along with concrete, epoxy and fiberglass to keep everything tight. Inside, workers erected scaffolding all the way to the top of the rotunda (185 feet above the floor) to repair damage to the domed ceiling and ornamental interior columns and plaster. Outside, at the very top of the dome, stone workers repaired the smaller masonry columns of the lantern. The lantern was damaged in the 1949 earthquake as well, but much of the original stonework remains. Keith Phillips, a stonemason from Tenino, carved new capitals to replace those broken in 2001.
"They reused much of the original stone [in 1949]," Schaefer says. "You can see how this has been repaired. It's just beautiful craftsmanship throughout."
Because the building is listed on the National Register of Historic Places and because federal funds were used for earthquake repair, all work must meet the standards of the Secretary of the Interior for a historic rehabilitation. The central effort of Phase Two is to upgrade the internal systems of the building -- plumbing, electrical, data, heating, air conditioning -- to 21st-century standards while retaining historic character and integrity. The process has much in common with modern surgical techniques, though writ very large.
"All of the conduits and all of the ductwork are being replaced in the building," says Schaefer. "All of the plumbing, all of the electrical has to be all new, and it has to go back in the same confines. The ductwork that's going in is a lot more substantial than what was there, so we're utilizing vertical masonry chases."
A sprinkler system is being added, he says, along with changes to make the building more accessible. "We will not be totally ADA-compliant, because there were some restrictions we couldn't overcome. But there will be a large measure of accessibility added. We're making it a lot more friendly."
Concurrently, the contractors are repairing earthquake damage to interior walls in the offices and public spaces of the building's four main floors. Some of the original plaster cracked, but only plaster that has separated from the underlying masonry may be removed.
"We found out which areas of the plaster were de-laminated by literally going around and tapping on it," says Schaefer. "Where it was hollow, we mapped it out. Our challenge now is to replace what's damaged and make it look like nothing's changed."
Construction is scheduled to be complete in November 2004 so the tenants can settle into their refurbished digs before the start of the legislative session in January 2005.