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PREPARING FOR A NIGHTMARE EARTHQUAKE BY PETER MURPHY, FM Journal September/October 1994 As the earthquake hit, the library's ceiling and overhead lighting came crashing down on tables and desks at which children sat quietly reading. It's a frightening scenario and one that nearly came true in Los Angeles on Jan. 17, 1994. Had the 1994 Los Angeles earthquake happened just a few hours later, this nightmare might have been a reality at the Northridge branch of the Los Angeles Public Library, which is located right near the epicenter of the 6.6 earthquake. When the results were totaled, the quake officially had killed 61 people and caused billions of dollars in damage. The Northridge library sustained heavy damage in the earthquake when hundreds of books fell off the shelves and the ceiling plaster and overheard fluorescent lighting fell down on to tables. Luckily, no one was in the library during the 4:31 a.m. quake. Meanwhile, at the Los Angeles Fire Department's Emergency Control center the building held up well structurally, but the overhead lighting system rattled and strained against its restraints. Both these cases highlight a hidden form of damage in earthquakes that is only just becoming understood by experts. However, it is clear that facility managers should be aware of how an earth quake can have a devastating impact on even the most modern building, both in personal injuries to its occupants and in the cost of repairing the damage. Earthquakes deliver two types of damage. First, there is the structural damage (collapsed buildings and fallen freeways) everyone sees on the nightly news. The second is a relatively unknown category generally involving building interiors (collapsed ceilings, fallen office lighting, toppled bookshelves and air conditioning units) called non-structural damage. It is only in the last few years that experts really have become aware of this second category. But all agree it=s important that people understand the hidden but very costly threat represented by non-structural damage from an earthquake. The supporting evidence for this opinion is mounting with each successive earthquake. A review of some of California's well-studied earthquakes from the past three decades indicates that while damage to building structures has been mitigated dramatically - unless they are located near the epicenter in which case it is much more difficult to hold damage levels to an acceptable level - the breakage now has shifted to the non-structural components, including the lighting, piping, air conditioning duct work, book shelvings, cabinets and false ceilings. This was demonstrated at the Northridge library when hundreds of books fell off the shelves, and the ceiling lighting and plaster tiles popped loose. For emergency planners, this destruction dramatically reinforces the standard earthquake rule of having people immediately get under a desk or table with the first shock wave, and making them stay there to avoid injury. The dollar value of damage done to non-structural components often can exceed that done to the building structure itself. This is especially true for many high-technology companies that have expensive computer and laboratory equipment. These will need protection not just from falling ceiling fixtures but also from water sprinklers that may go off accidentally under the stress of the seismic disturbance. For instance, while the San Francisco (epicenter at Loma Prieta) earthquake of Oct. 17, 1989, saw most modern high-rise buildings up to 50 stories escape without structural damage, a number, such as a 12-story apartment buildings (sic) around Lake Merced and a dormitory on the San Francisco State University campus, suffered non-structural damage. A dramatic illustration of the threat to life came during the ceiling collapse of the heritage Geary Theater in San Francisco. Its non-structural components, along with the fallen ceiling lighting r\grid and mounds of ceiling plaster, came to rest in a pile of rubble on the floor, which covered the first six rows of seats in the auditorium. Fortunately, the theater, which accommodates 1,350, was not in use at the time of the earthquake. In addition, common in-building injuries result from shifting equipment, objects falling off the wall or from falling parts of light fixtures or ceilings. More than 80 percent of all hospital visits in the Loma Prieta event were a result of head injuries, many of which may have been caused by falling objects. Light fixtures also are of great concern, especially in high-occupancy buildings such as libraries, hospitals, schools and other public buildings. With their fluorescent light fixtures, public schools are a high risk area during an earthquake. If they fell down in a classroom while school was in session, injuries, and even casualties, could be numerous. Researchers at lighting manufacturer Ledalite Architectural products found that suspended lighting fixtures are particularly susceptible to seismic forces. Building codes often require such systems to be braced to prevent undue swaying during earthquakes and to take the sudden loads that can be delivered by seismic forces. To comply with these codes, many older buildings require retrofitting of their lighting systems. Such work not only improves the lights reliability in a seismic emergency, but also allows facility managers to take advantage of energy savings available by using state-of-the-art technology. Why is there this apparently sudden surge of non-structural damage? Probable because prior to 25 years age, the structural damage from earthquakes was to overwhelming that the building was demolished completely, leaving little evidence of the relative weakness of the non-structural components. Tough seismic building coded implemented midway through this century have resulted in leaving the building structure intact after more recent earthquakes, allowing the non-structural damage to be evaluated more closely. In the last few years, the dollar costs associated with non-structural damage have risen considerable. For some, the replacement of damaged high-tech electronic and computer equipment found in their building would cost more than the building itself. One reason is the increasing complexity of modern buildings, something that facility managers are very aware of in their own day-to-day work. Areas of concern for facility managers There are four key areas that managers need to be aware of when assessing the potential impact of earthquake damage on a building. These are life safety, property damage, continuity of operation and legal liability. In life safety, the primary concern of all building regulations and seismic building standards is to prevent loss of life or injury. Seismic structural regulations can be successful in preventing the structure's collapse, but non-structural elements present a threat to life and limb. Obviously, the life safety issues of a warehouse are dramatically different from those of an office tower. Property damage has a traditionally low emphasis as a concern of the public and as a government policy issue. However, form a building management perspective, managers must be concerned with avoiding or reducing the extraordinary costs associated with such seismic induced damage. A concern since the 1971 San Fernando, Calif., earthquake has been maintaining a facility's integrity of operation during a seismic emergency. This is extremely important with public safety facilities such a hospitals, fire halls, schools, public works and police stations. At the lease, hospitals, fire departments and emergency disaster centers must be capable of operating in a normal manner both during and after an earthquake. In addition, schools must be available as community emergency relief centers. In the 1971 earthquake, two hospitals were rendered unusable. In addition, their ambulances were crushed under the collapsed garage roof. In the powerful earthquake that hit Managua, Nicaragua, years ago, the central fire station doors were rendered inoperable, trapping the fire trucks inside while the fires started by the quake raged outside. Building designers and facility managers need to ensure that essential services in the building will be operable and available in the event of disaster. Of crucial importance are the exit hallways, emergency lighting, fire sprinkler systems, exit stairwells and main lobby areas of most public buildings. In recent years, legal liability concerns for injuries suffered during an earthquake have emerged. This is becoming a major issue for insurance companies and occurred most recently after the 1989 Loma Prieta earthquake where lawsuits were filed after casualties were sustained in buildings that took both structural and non-structural damage. the suits were settled out of court so they weren't tied to negligence on the part of building owners but the potential for ground-breaking suits increases with each earthquake. While the integrity of the building structure itself always is of primary importance, even non-structural building elements (e.g., suspended light fixtures and pre-cast exterior cladding components) have been known to cause loss of life or injury during an earthquake. In today's world of extreme exposure to professional liability, facility managers and the people they assign to seismic safety need to understand the legal concerns. Another financial concern is insurance. With the rising costs of damage claims resulting from recent natural calamities such as Hurricane Andrew and the Midwest floods, insurance companies are taking steps to review management's emergency preparedness practices in the buildings they insure. Although major loss of life has been avoided in the United States' two most recent earthquakes, the odds are increasing rapidly that the next big shaker will occur during business, school and library hours. For facility managers, it just makes professional sense to do what is necessary now to be ready in case that nightmare scenario becomes reality. IFMA ABOUT THE AUTHOR: Peter Murphy is president of Ledalite Architectural Products Inc. of Langley, British Columbia. Ledalite designs and manufactures seismic-resistant overhead fluorescent lighting systems for schools and universities, transit stations, offices and commercial buildings and retail stores throughout North America. A more detailed review and summary on current engineering seismic standards for building lighting systems in North America is available from Ledalite by calling 604/888-6811 and asking for the report "How safe is your lighting sytem?" or check in at www.ledalite.com
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