Advertisement
YOU ARE HERE: LAT HomeCollections

Quake-Proof Heritage : Seismic safety: Tremors won't trouble UCLA's venerable Kerckhoff Hall once a system is installed to cushion it from ground movement.

May 16, 1991|DUKE HELFAND | TIMES STAFF WRITER

Picture for a moment UCLA's venerable Kerckhoff Hall as a major earthquake shakes the ground below. The delicate stained-glass windows jiggle ever so slightly. Students inside, stretched out reading on antique couches, miss barely a word as the quake rumbles by.

Fantasy? Wishful thinking? No. New earthquake technology soon to be employed at the 62-year-old UCLA landmark makes such a scenario likely.

Although the technology has been used in other buildings, Kerckhoff Hall will be the oldest building in California to be seismically upgraded with the so-called base-isolation system.

The 13-million-pound, mostly brick building will sit atop 180 shock-absorbing pads made of lead, rubber and steel, and a 1 1/2-foot moat will extend around its perimeter.

The idea is to reduce the shock to the building during a quake by separating it from ground movement with the moat while also allowing its walls and foundation to respond uniformly to shock waves with the help of the pads.

Project architects estimate that the moat and the pads combined will reduce the effect of a magnitude 8.0 quake to that of a 5.0 quake.

In real terms, Kerckhoff Hall will be able to withstand a quake with nearly 10 times more destructive force than the one that rocked the San Francisco Bay Area in October, 1989, with no major structural damage and without having to close down, the architects say.

"To someone inside the building, an earthquake will feel like thumping on the floor," said Jorge Sciupac, a partner with Widom Wein Cohen, the firm designing the system in conjunction with architectural consultant Rebecca Binder. "By allowing the building to move freely, columns and beams won't bend or break. There will be very little movement. Kerckhoff Hall will probably be one of the safest buildings on campus."

Kerckhoff Hall, built in 1929, was among the first six buildings on the UCLA campus. Originally, its wood-paneled rooms served as the student union and housed the office of the university president. Today, it serves as a center for student government activities, housing dozens of organizations and the school's daily newspaper.

School officials, fearful that the building's aging columns would one day crumble under the strain of even a moderate quake, viewed base isolation as the surest way to protect the structure and the people inside it.

The conventional approach to seismic upgrading involves thickening walls with concrete and steel, which would have destroyed architectural details that school officials and alumni say are part of the building's historical significance.

Much of the ornate terra-cotta filigree and brickwork on its exterior would have been lost during construction to thicken the walls. Inside, ceilings decorated in serpentine patterns of blue and gold likewise would have been ruined.

"It would have been nearly impossible to replace the detail work," said Julie Davis, project manager for Kerckhoff Hall Life Safety Renovations. "That wasn't acceptable to the architects, to the university or to the students. I don't think that anyone was willing to destroy a hallmark of the campus."

There were other considerations as well.

Although conventional upgrading would have required closing much of Kerckhoff Hall during the 18-month construction process, only the first floor of the building will be closed while the base isolation pads are installed. Construction crews will excavate six feet under the building to install the pads.

Also, Davis said, designers of the base isolation system predict that the building will be operable almost immediately after a quake, unlike buildings that are conventionally upgraded.

Since 1987, when an engineering study identified the building as structurally deficient, student organizations have been debating how best to preserve it.

One informal proposal was to tear down the building and replace it with a modern structure. But school officials and student representatives alike rejected that idea.

"Ask people what they remember about their years at UCLA and they will say Kerckhoff Hall," said Mark Panatier, the school's student union director. "It's the seat of student government on this campus, just as it has been for 60 years."

The student board of directors voted in early 1990 to endorse the base isolation system over conventional upgrading. The $21-million cost of the project will be paid through an annual $79 fee tacked onto tuition bills over the next 27 years. Conventional upgrading would cost about $11 million.

Panatier said work is expected to get under way by June, 1992. When it is completed, around January, 1994, Kerckhoff Hall will join only a handful of buildings in the United States that use the base isolation system.

The Foothill Communities Law and Justice Center in San Bernardino County was the first new building in the country to employ the technology. A similar system is being designed for a new Kaiser Permanente data processing center, also in San Bernardino County.

Although the concept of using shock-absorbing pads to protect buildings from earthquakes has been around for nearly a century, the computer technology needed to design such a system became available only in the last decade.

Making Buildings Quake-safe

A building with a conventional foundation would sustain damage because ground movement is amplified on higher floors.

Base isolation pads act as seismic shock absorbers during an earthquake. Movement takes place at the level of the isolators and is not transferred to the building.

Advertisement
Los Angeles Times Articles
|
|
|