Renovation project to tie down Capitol dome, fix quake damage

OLYMPIA — When the Nisqually earthquake shook the Capitol, the historic building's dome and the barrel-shaped structure that supports it were just sitting on the main part of the building.

No gigantic bolts, no massive iron fasteners. Just 58 million pounds of sandstone and other materials, squatting on a massive ring that looms above the soaring rotunda that separates the House chamber from the Senate.

"When I say sits, I mean sits," Marvin Doster, senior project manager for the M.A. Mortensen Co., the contractor overseeing the $100 million Capitol renovation, said yesterday during a tour of the work. "It's gravity. There's nothing holding it together."

When the quake hit nearly two years ago, those pieces moved. The dome shifted, along with the sandstone columns that hold it up. Structural walls and decorative stonework cracked. Interior plaster showered down. Lawmakers and lobbyists fled in terror.

The first part of the renovation — about $10 million worth — is aimed at repairing the damage the quake caused — and tying the structure down so a future quake won't break as much.

Steel rods will stabilize the columns. Pins will anchor blocks of stone on the exterior. A high-tech fiberglass corset will encircle the interior dome to keep it together in a future quake. Reinforced concrete will tie interior and exterior walls together and clamp the whole thing down onto what Doster calls "the tabletop."

And that's just phase one of an overhaul scheduled to take two years. Phase two will replace outdated plumbing, ventilation, electrical and communications systems — and reconfigure the jumbled ground-floor rooms. The work is being paid for with money from a special fund for maintenance of the state-capitol campus. Income from state lands fills that fund.

When the building reopens, visitors won't see much difference in its main public spaces. Most of the work, Doster said with a sigh, will be too high to see or hidden behind walls and ceilings.

"People will say, 'What have you done?' " he said. "We'll say: 'We've done nothing to change the beauty of the building.' "

When the Legislature convenes next week, lawmakers will meet in cramped temporary quarters just a few hundred feet away. But from an architectural point of view, they'll be miles from home.

No dome soaring above the gleaming state seal in the rotunda. No gray-and-black-streaked marble shipped in from a remote Alaskan island.

Designers, engineers and workers have marveled at the structure's toughness since the project began, Doster said. The building was opened in 1928.

"They used quality materials, quality craftsmanship," Doster said. "They did it right."

But quake-proofing was in its infancy then. The Capitol has survived three major earthquakes since its construction, in 1949, 1965 and 2001. Each time, improvements have been added.

A reinforcing wall added after the 1965 quake gets much of the credit for keeping the building standing in the 2001 shake.