State's buildings prepared for earthquakes

Nevada State Archives A man sprays gunite, a form of concrete, onto steel reinforcing to create a concrete building within a building to protect the Capitol, right, from earthquakes in the 1970s.

Nevada State Archives A man sprays gunite, a form of concrete, onto steel reinforcing to create a concrete building within a building to protect the Capitol, right, from earthquakes in the 1970s.

Some of the oldest buildings in Northern Nevada and potentially most vulnerable to earthquake damage are owned by the state itself.

The issue was raised because of swarms of small and medium quakes centered in the Verdi area over the past few weeks.

But experts say those century-old masonry buildings - including the Capitol - have been prepared to handle a quake.

During the past 30 years, the Capitol, its octagonal annex, the State Museum, the old Ormsby County Courthouse, the former federal post office and district court - now home to the tourism commission - and the old state printing building have all undergone extensive structural work designed to help them survive a big quake.

The 137-year-old Capitol underwent the most extensive reconstruction.

State Archives Manager Jeff Kintop said that project was made necessary after western Nevada was reclassified into the same earthquake zone as San Francisco.

Three independent engineering firms declared the Capitol "structurally unsound" and "a public safety hazard." In a good quake, they said, the floors could separate from the walls and the stone exterior collapse.

Kintop said that left the state with two options: Tear it down and build a new one or completely reconstruct the historic Capitol.

The 1977 Legislature appropriated $6 million to rebuild. McKenzie Construction of Sparks went to work that year, removing the roof and dome, taking out the floors and the stone interior walls, leaving only the exterior walls.

"It looked like bombed out Dresden," said Kintop.

An extensive system of steel and rebar was installed into the inside of the sandstone blocks that make up the Capitol's exterior. Then concrete was added, new concrete and steel floors were poured and tied into that shell, the lumber roof structure replaced with steel beams and a new, much lighter fiberglass dome put atop the reconstructed Capitol.

In effect, they created a concrete and steel building inside the old sandstone building.

"The inside of the building is being supported by this structure that's independent of the outside walls," said Robbie Oxoby of the Public Works division. "The whole idea is that, even if there is damage to the outside walls, the interior of the building would be OK.

"Basically, the only thing that's original is the exterior."

When they finished the structural work, workmen put the original decorations, marble floors and wainscoting and decorative elements back in their original places, making the interior look like it did when it was new. Even the original staircases, railings and balusters were put back.

But, at the time, lawmakers didn't believe the state could afford to do the same to the 100-year-old annex behind the Capitol. The annex, originally built as the state library at the turn of the century, didn't get the same treatment until 2005.

Central Sierra Construction crews gutted the annex and used the same system of steel reinforcement and sprayed-in concrete to stabilize the exterior walls. Then they rebuilt the interior, trying to keep and restore as much of the original moldings, pillars and other elements as possible. It now houses six modern offices on the main floor with a high-tech media and meeting room upstairs.

Of those original state buildings, only the museum - originally the Carson City Mint - has actually suffered earthquake damage. It was closed to the public after the 1990 earthquake that hit the Bay area caused structural damage that threatened to separate floors and the roof from the sandstone walls. Museum Facility Supervisor Scott Klette said Clark and Sullivan of Reno submitted what state officials said was a very low bid of less than $1 million to do the repairs. He said the company came through, using hundreds of steel braces and straps to stabilize the building by tying walls, floors and roof together.

"It was a life-safety issue, not a preservation issue," said Klette.

He said museum crews had to get into the act as well, disassembling all the exhibits and removing them from the building so workmen could do the job.

"We had to gut the mint," he said.

Just about the only thing that didn't get moved was the historic - and extremely heavy - coin press.

The State Printing Office, completed in 1886, is Nevada's second oldest state building after the Capitol. It got its rebuild when the new state library and archives building was built around it in 1993. Kintop said workmen there didn't want to build a concrete structure inside because the building was so small to begin with. So, he said, they reinforced the walls with steel bars by drilling vertically through them and inserting the steel.

The Ormsby County Courthouse, built in 1922, is one of two structures on the list that, originally, wasn't a state building. But it too is sandstone from the same quarry east of town. Again, Clark and Sullivan of Reno did the work, carefully removing much of the interior with the idea of putting elements including the marble entry walls and floor back in place afterward.

Oxoby said more joists were added to the first floor where the Carson City court clerk's numerous file cabinets had caused it to sag. And again, he said, much of the work involved tying the walls and floors together.

The Laxalt Building, now home to State Tourism, was built by the federal government in 1891 as the post office and district court. It is the only building on the list made of brick instead of sandstone. Oxoby said that building, which was deeded to the state in 1970, was structurally stabilized before it was remodeled into Tourism's new home. He said it has had the necessary improvements made to ensure it won't just collapse in a quake.

Public Works Manager Gus Nuñez said unreinforced masonry buildings are more likely to suffer major damage in a quake than the normal stick-built home.

"Lumber is flexible," he said. "Masonry is rigid."

A wood-framed house will flex in a quake and, although damaged, almost always remain standing. With unreinforced masonry buildings, he said, "you get a good shake, the wall falls down."

The solution, he said, is to tie walls, floors and roof all together. He said the state still has a number of those buildings, but does as much as possible to make them safer with every project. He said on a number of roofing projects at Stewart, for example, the state has taken that opportunity to install braces and ties to better connect the roof to the walls of those buildings.

"The idea is to minimize building damage so people can get out and safely away from the structure," he said. "Anytime we have a building that's unreinforced masonry, that would raise a flag for us."

Asked about the Kinkead Building, now vacant because of concerns it isn't safe, Nuñez said it would take a major quake - and one that actually caused the building to twist, rotate around its concrete core - to collapse the structure. But he said it's a moot point now since the building is vacant and mothballed until the state can fund its demolition.

• Contact reporter Geoff Dornan at gdornan@nevadaappeal.com or 687-8750.

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