Hospital Puts Safety First--Seismic Safety, That Is

If a major earthquake ever hits San Bernardino’s new county hospital, it’s designed to react like a building in a big bathtub.

It would move, all right, but more slowly and less forcefully than the ground around it, according to the engineers who have designed the five-building Arrowhead Regional Medical Center, set to open early next year.

Key seismic safeguards? A bed of giant, circular “base isolators,” made of bonded layers of rubber and steel, are sandwiched between each building and its foundation. Multiple shock absorbers connect each building with its cushion bed. A series of portals connect the center’s main, six-story patient tower with a diagnostic and treatment center and an outpatient clinic.

If the Big One should strike, “that’s the place I’d hope to be,” said Michael Bolen, president of Newport Beach-based McCarthy, which co-managed the hospital’s construction. “It’s the one hospital that’s got by far the highest likelihood of being in operation afterward.”

Built by McCarthy’s joint venture with the Japanese firm Obayashi Corp., the medical center in Colton will replace the county’s existing hospital, now considered outmoded. The new center--intended to withstand an 8.3-magnitude quake--borders two significant faults--the San Andreas and the San Jacinto. The faults are seen as capable of at least a magnitude-7 quake.

Three years ago, serious questions arose over cracks that appeared in metal welds used in the project’s construction. However, state, hospital and construction officials say any with cracks were fixed and their worries over welds are gone.

Dave Ring, a structural engineer for California’s Office of Statewide Health Planning and Development--the agency in charge of hospital building standards--describes the building’s “base isolation” as “state of the art” and much more forgiving of seismic movements than the traditional “fixed-base” structure.

Barbara Marsh covers health care for The Times. She can be reached at (714) 966-7762 and at barbara.marsh@latimes.com.