Designed to Function During Earthquakes

Building a major 9-1-1 emergency communication facility atop an earthquake fault zone is a structural engineering challenge. It becomes even more difficult when the building must continue to function during, and after, a major quake. The engineering/architectural firm, Fluor Global Services met the challenge. Located less than 5 miles from the Rose Canyon Fault, the new San Diego Emergency Communication Complex (SDECC), is a two-story, 38,000-square-foot essential services facility designed and constructed using base isolation technology and building materials and systems with the structural integrity and flexibility to cope with the inevitable earth tremors.

"To meet the owner's performance objectives, we chose a base-isolated structure to maximize the continued function of important communications equipment after an earthquake," says David Rembert, Director of Design and Engineering for Fluor Global Services. "We incorporated a seismic base-isolation system designed to withstand quakes as great as 7.0 on the Richter Scale." Rated the most effective and economical method of protection against earthquakes, base isolators are large rubber and steel bearings that act as shock absorbers. Each of the SDECC's 26 columns are placed on a base isolator which is designed to move up to 14 inches (355 mm).

"Our building design calls for a translucent exterior cladding, used on two sides," explains Rembert. "This satisfies the need for security yet still allows natural light to enter the building while minimizing the area of glass. We chose a Kalwall translucent curtainwall system."

Kalwall employs a system of interconnected structural components that form rigid, modular units, replacing the heavy mullions and floating panels of other curtainwalls. Kalwall's time-proven Clamp-tite installation system gives intrinsic flexibility to the panel, allowing for movement when either high wind loads or seismic activity stress a building's structure to the point of movement. Normal loads are dispersed throughout the panels, rather than converging on the mullions. Clamp-tite closures at head, sill, jamb, and unit-to-unit serve only a sealing function and allow for movement.

The $5.3 million SDECC consolidated the Sheriff's Communications and Data Center, the Office of Disaster Preparedness and radio and computer support for the county's Department of Information Services into a three-building complex. The amount of activity this building sees is astonishing. The Sheriff's dispatch room handles an average of slightly more than 1,600 calls daily, both emergency and non-emergency. "The design is user friendly," says Rembert. "We wanted a design to relieve stress and to make it a very pleasant place to work."

Compared with the county's old dispatch facility, most dispatchers say it is "like going from a 1965 Volkswagen to a 1999 Cadillac." With a lack of windows and poor lighting, the prior facility was dark and gloomy. For those who worked there, it was easy to lose track of time. It was an "us or them" mentality thanks to the dividers that separated the call takers from the dispatchers. Poor overhead lighting added to the problem of computer glare.

"With plenty of input from the public-safety personnel, we designed an atmosphere of spaciousness and connection to the outside world," states Rembert. "Instead of lining up back-to-back, dispatchers are grouped together by emergency and non-emergency call areas in one large, open room with an abundance of windows, and calming tones of soft blue and green add to a sense of openness. Forty-eight work stations spread out concentrically eliminate barriers, while each station can be customized by moving hydraulically driven computer platforms up, down or sideways so that one can stand, sit or even lean while typing in a report."

Wide, heavily carpeted corridors feature ramps traveling room to room to accommodate disabled employees. Fluor Global Services included a "Quiet Room" in their design; furnished with only a simple couch and soft chair, this space is set aside for dispatchers needing to relax.

"Kalwall translucent exterior wall panels allow 15% outside light into the building," states Rembert. "Kalwall, combined with indirect lighting that is evenly distributed throughout the interior, creates balanced lighting." Kalwall's diffuse light properties deliver the best quality of balanced natural daylight while eliminating glare and shadows associated with traditional glazing. Even on cloudy days, usable natural light fills the interior. Kalwall offers light transmission ranges from 3% to 75%.

"The architectural system was designed to conceal the base isolation system and its associated 'free space'," explains Rembert. "The distributed systems entering the building were designed to accommodate the large seismic movements allowed by the base isolators. Structural tubes were used for bracing. These attractive structural elements were left exposed in many parts of the building. The Kalwall panels added to the effect of allowing the inside light to filter through at night, which allows the structural framing to be visible from the exterior."

"Dealing with a limited budget caused us to look at every design decision from a cost beneficial analysis standpoint,"says Rembert. The unique construction and extreme structural strength of the Kalwall components permit the largest panel-unit sections to be installed quickly and efficiently. Pre-engineered and prefabricated, the Kalwall panel-units eliminate superfluous structure. "The SDECC was budget-driven by a fast-track construction of 10 months."

Unique in many ways. . .
The SDECC is as unique in its appearance as it is in its construction. "From the air, it looks like a stealth bomber," says Rembert. "The building footprint is highly irregular in plan because the facility is situated at an oblique corner of the county's land adjacent to two existing property lines."

The County of San Diego Emergency Communications Complex possesses unique characteristics such as: the integration of a structural system with architectural, mechanical, electrical and other systems; functionality and survivability; and technical innovations -- the building's superstructure and foundation system were designed to satisfy the 1994 UBC Seismic-Isolation Requirements. It's designed to survive and, given its operational importance, is a safety net for the county. . . as eye-pleasing as it is functional!

Engineer and Architect: Fluor Global Services

Kalwall Specifications:
Exterior face: aqua
Interior face: white
"U" factor: .29 (1.25 W/m²k)
Light transmission: 14%
Shading coefficient: 0.19

For more information, contact:

Bruce Keller
Kalwall Corporation
1-800-258-9777