The Earthquake Engineering Online Archive

Studies of a 49-story instrumented steel structure shaken during the Loma Prieta earthquake

Chen, Cheng-Chih; Bonowitz, David; Astaneh-Asl, Abolhassan

UCB/EERC-92/01, Earthquake Engineering Research Center, University of California, Berkeley, 1992-05, 136 pages (705.326/1989L/C53)

Results of dynamic elastic time history and response spectrum analyses of a building shaken during the 1989 Loma Prieta earthquake are compared with actual responses recorded by the California Strong Motion Instrumentation Program (CSMIP). The building, constructed in 1979, is a 49-story office tower in downtown San Francisco with longitudinal moment-resisting steel frames and transverse eccentrically braced steel frames. Mathematical models of the structure, considering a range of values for three of the modeling parameters, were subjected to ground accelerations recorded by CSMIP at the basement level. Modeled and recorded floor displacement time histories are compared for a variety of models, and results are discussed in terms of design criteria sufficiency. Inelastic two-dimensional models of a typical frame are also constructed to conduct the nonlinear dynamic analysis. The computer models are subjected to base excitations recorded during the 1989 Loma Prieta earthquake as well as to the strong ground motions obtained by scaling-up the peak accelerations of the Loma Prieta record as well as a hypothetical San Andreas M8 plus event to simulate a major earthquake. Trends in the inelastic behavior of the structure are observed from these inelastic analyses.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-92-01.pdf (4 MB)