CSU East Bay landmark building ready to implode

  • August 15, 2013

By David Perlman
Chronicle Science Editor

A landmark steel and concrete building, towering high in the East Bay hills and condemned as an earthquake hazard, will fall in a powerful series of timed high-explosive blasts Saturday.

On Wednesday, a team of experts known as "blasters" began placing dynamite and a powerful explosive called RDX to bring downWarren Hall, where generations of students and administrators at the California State University East Bay campus in Hayward had studied and toiled since 1971.

Imploding the 13-story building is in the hands of Controlled Demolition Inc., a Maryland firm known for destroying skyscrapers, bridges, towers and chimneys around the world for more than 65 years.

On Wednesday, Warren Hall was tightly controlled, an empty shell surrounded by chain-link fencing and patrolled by campus police and sheriff's deputies.

J. Mark Loizeaux, president of the demolition company, assured a visitor that the scheduled "implosion," set for about 9 a.m. Saturday, will pose no hazard to nearby buildings or people, or to homes and offices anywhere in Hayward or beyond.

"It will have no impact on anything on or near the campus," said Loizeaux, whose father, a professional forester, founded the company in 1947. "What we do is very predictable and very safe. We will be monitoring the ground motion from the explosion, although any vibrations will be extremely faint."

Close to a fault

Warren Hall has been empty since January 2011, after the structure was deemed the worst seismic hazard in the California State University system. It stands only 2,000 feet from the Hayward Fault, which scientists have long warned is the most likely among all the faults in the San Andreas system to next rupture into a large earthquake.

"We call bringing down Warren Hall an implosion," Loizeaux said, "We're often called on to control blasts so tightly when a building is extremely close to other structures, and the entire building must fall in on itself entirely within its foundation perimeter.

"But Warren Hall stands next to an empty hillside, and weighs some 12,500 tons, so I'd call this more of a toppling - although I'd be very surprised if any of it falls more than 35 feet away from its foundation."

The demolition will require 750 sticks of dynamite to destroy the reinforced concrete walls of the understories, and 320 shaped charges of RDX for the steel girders, Loizeaux said. It will take 13 to 14 seconds for the entire building to fall, "that's after I say 4, 3, 2, 1 - and fire!" he said.

In Bakersfield earlier this month, a man lost a leg and four other people were injured during the demolition of two towers of a PG&E power plant by a different company when chunks of the wreckage flew into a crowd of more than 1,000 spectators.

Keeping people safe

No spectators will be injured, Loizeaux said, because the Warren Hall blast will be so tightly controlled that debris will only fall close to the explosion site.

In fact, spectators won't be allowed anywhere near the implosion site. In preparation, the entire Cal State East Bay campus of 343 acres will be closed to the public at 8:30 p.m. Friday and will not be reopened until 6 a.m. Monday.

Although Loizeaux predicted that ground tremors from the explosion will be extremely small, scientists from the U.S. Geological Survey, Cal State East Bay, UC Davis, UC Berkeley and other institutions are placing a wide network of seismic sensors on the ground for miles around the blast site.

Their seismographs will record the effects of 12,500 tons of steel and concrete as it hits the ground in one big mass and spreads seismic signals across the Bay Area.

The seismographs could help scientists detect unknown faults long hidden beneath the East Bay's sediments and understand the varied distribution of the next big earthquake's ground shaking as it hits flatlands and hills, said geologist Rufus Catchings of USGS in Menlo Park.

The sensors will also help scientists determine how fast seismic waves from a future Hayward quake are likely to travel through the East Bay terrain, he said. It could provide a critical calculation for other scientists at Berkeley who are now developing "early warning" instruments that could save lives when the next big one hits.

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