Taking tall buildings' faint pulse
In response to the terrible events of Sept. 11, 2001, the Council on Tall Buildings and Urban Habitat at Lehigh University in Bethlehem, Pa., recently convened a public symposium, "Assessing Tall Building Safety," to present and discuss the findings of a special task force it had created last fall.
The group had met several times over the past 10 months, but it had not gone before the public until May 31 in New York City. That event drew about 100 interested building industry experts, plus other CTBUH members and representatives of the national press. Throughout the course of the day, the audience heard several reports on such important findings as the public's need for greater education on how buildings work and on what owners and occupants each can do to increase safety
In general, however, CTBUH Chairman Ron Klemencic cautioned against an industry over-reaction to Sept. 11. The magnitude of that day's events is well beyond any that we should consider in the design of high-rise buildings, said Klemencic, president of structural engineer Skilling Ward Magnusson Barkshire Inc., Seattle. There are things we can do to improve the safety of our built environment, he added, but they should not include sweeping building code changes.
Indeed, although the terrorist threat may seem high now, that is not really the case, argued Stephen DeSimone of DeSimone Consulting Engineers, New York City. His report to the group concluded that natural disasters such as earthquakes and windstorms pose significantly higher risks than any future terrorist attack. Even so, he presented several steps owners can take now to minimize the risks.
Focusing on infrastructure vulnerability, Robert Prieto, chairman of Parsons Brinckerhoff Inc., New York City, called for the immediate assessment of building capacity, redundancy, and reliability of critical systems. He defined "critical" as: systems where rapid failure would lead to catastrophic loss of life; whose failure or significant degradation would lead to unacceptable economic consequences; or whose rapid failure would hinder rescue, response and recovery efforts.
"We presently have an inadequate understanding of the growing and ever-more complex [built environment]," Prieto said. Of note, PB is working with local architect Beyer Blinder Belle on a master plan for redeveloping Ground Zero.
One attempt to simplify future building systems could involve the combining of stairs and freight elevators into one unit that can be pressurized and reinforced, added Jeff Heller of Heller Manus Architects, San Francisco. Doing so could yield several benefits at little additional cost, including the creation of a refuge area for the disabled and injured on every floor, Heller noted.
All told, the task force's findings and recommendations can be found in two new CTBUH publications: "The Building Safety Assessment Guidebook," and "The Building Safety Enhancement Guidebook." Both are now available on the Council Web site at www.ctbuh.org.