Earthquakes: A New Look at Cracked Masonry

Langenbach, Randolph; ,

Earthquakes: A New Look at Cracked Masonry

by Randolph Langenbach, Tech. Consultant; Federal Emergency Management Agency, San Francisco, CA,

Serial Information: Civil Engineering—ASCE, 1992, Vol. 62, Issue 11, Pg. 56-58

Document Type: Feature article

Abstract:

Economics, fears of liability, and a strict damaged-buildings repairs ordinance have contributed to an extensive delay in the repair of masonry-infill buildings in earthquake-stricken Oakland, Calif. This delay has had a devastating impact on the economic well-being of Oakland's downtown. Three years later, several of the most significant historic downtown office buildings remain abandoned and threatened with demolition. Surprisingly, most of the city's older unreinforced brick buildings came through with little damage. In fact, Oakland has become the first U.S. city in earthquake history to suffer extensive damage, not to its older unreinforced brick buildings, but to its major early 20th century steel-and-concrete frame downtown buildings. The city's 18-story city hall (built in 1912), along with about 15 other major downtown multistory buildings, remains closed. Following the Loma Prieta earthquake, Oakland enacted the Damaged Building Repairs Ordinance, which prevents owners from repairing the damage. Instead, any structure that, according to a specific engineering analytical procedure, has lost over 10% of its pre-earthquake lateral capacity must be upgraded to a slightly modified version of the 1988 Uniform Building Code at what is enormous cost. The standard, static procedures of this code have proven economically-incompatible with infill-frame construction.

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