Southern California healthcare facilities built before 1973 are more likely to fail in a powerful earthquake than newer or retrofitted structures that have been "quake-proofed."
In the wake of the Jan. 17 earthquake and 5,000 aftershocks that rocked the Los Angeles area, architects are warning that many of the region's existing healthcare facilities aren't designed to be operational should a catastrophic earthquake occur.
Information obtained by MODERN HEALTHCARE from California's Office of Statewide Health Planning and Development and operators of individual medical centers, outpatient clinics and buildings shows 34 hospital buildings and medical office complexes sustained damage from the powerful 6.8 temblor (Jan. 31, p. 6).
Of those structures, two hospitals and four skilled-nursing centers remain closed to inpatients while 11 hospitals continue to offer limited services. Although most hospitals have reopened all services, extensive damage has forced many providers to establish alternative care sites while structures are repaired or razed (Feb. 28, p. 14).
"Any building built before 1973 is suspect (to require seismic reinforcing) and is more vulnerable to experiencing significant damage than newer buildings," said David Burdick, a principal architect of Bobrow/Thomas and Associates in Los Angeles.
Mr. Burdick said many of the buildings that faltered during the January quake failed because they weren't constructed with appropriate state-of-the-art reinforcements that absorb a quake's impact.
Ken Lee, a principal in the Santa Monica, Calif.-based architectural firm of Lee, Burkhart and Liu, said stronger anchoring of equipment to walls and ceilings and heavier-gauge metal in stud walls and in wall-backing are ways to avoid quake-related damage in older buildings.
Most structures were constructed using a "fixed-based design," in which buildings are anchored to the earth through large pilings or spread footings, Mr. Burdick said. Those structures are inflexible and unable to handle forceful tremors, he noted. That results in heavy jolting and shaking, and facilities ultimately sustain heavy internal damage.
A design that building planners consider state-of-the-art technology to help structures withstand the much-anticipated "Big One" uses the concept of "base isolation" to make structures earthquake-proof.
This method, which works much like a shock absorber on a car, allows a structure to roll and sway with the quake's motion. Isolater beams, made of a flexible, rubber-lead compound and erected beneath a building, are designed to withstand a quake as powerful as 8.3 on the Richter scale.
Both architecture firms are using base-isolation design in projects currently on the drawing boards.
Mr. Burdick's firm is using base isolation in the $405 million San Bernardino County Medical Center in Colton, Calif., and Mr. Lee's firm has included the earthquake-proofing plan in its design of the $800 million LAC-University of Southern California Medical Center. Both are replacement facilities.
Meanwhile, concern over hospitals' preparedness to survive a major temblor has prompted State Assemblyman Burt Margolin (D-Los Angeles), chairman of the Assembly Health Committee, to propose legislation requiring older hospitals to meet the same stringent requirements demanded of hospitals built after 1973.
Seismic safety legislation was passed in the aftermath of the 1971 Sylmar earthquake that destroyed two hospitals.