| Description |
Central School in Tooele, Utah, is a three-story building with unreinforced masonry bearing walls. Its concrete floors and roof are supported by steel beams; other structural members, including beams and columns, are of reinforced concrete. The structure was built about 1930, when seismic building standards were not adopted in Utah. Recently, there has been much concern and study regarding the probability of a major earthquake along Utah's Wasatch Fault. Tooele City is close enough to the Wasatch Fault to be affected by a quake there plus there are many small fault scarps nearer Tooele, notably the Oquirrh Fault, capable of generating magnitude 7 earthquakes. Various geologic studies indicate that, for a time period of 50 years and a 90% probability of nonexceedence, peak horizontal ground acceleration in Tooele may be from 10% to 20% of g. An earthquake of this magnitude could damage the main load-bearing system of Central School. The structure's lateral force resisting elements--unreinforced masonry walls--are too few and too brittle to withstand serious groundshaking. In addition, parapets, tops of pilasters and a tall smokestack could break loose and fall during a quake. The original school building's seismic deficiencies could be repaired for $200,000 to $250,000. This cost would include building new reinforced concrete shear walls, bracing the parapet, securing tops of pilasters and removing the smokestack. |
