The Earthquake Engineering Online Archive - (Nisee e-library)

Optimal design of seismic-resistant planar steel frames

Balling, Richard J.; Ciampi, Vincenzo; Pister, Karl S.; Polak, Elijah L.

UCB/EERC-81/20, Earthquake Engineering Research Center, University of California, Berkeley, 1981-12, 124 pages (620.1/B23/1981)

This report presents a method for the seismic-resistant design of planar rectangular braced or unbraced steel frames. An important feature of the method is that nonlinear step-by-step integration is used as the analysis technique within the design process itself. The method directly quantifies the accepted seismic-resistant design premise that a structure: (1) resists moderate ground motion without structural damage and (2) resists severe ground motion without collapse. Actual ground motion accelerograms are selected and scaled to levels representing moderate and severe ground motions. Constraints quantifying structural damage and limited nonstructural damage are constructed for cases of moderate ground motion. Constraints quantifying collapse and limited structural damage are constructed for the case of severe ground motion. In addition, there are serviceability constraints on structural behavior under gravity loads. Possible objective functions range from the minimization of structural volume to the minimization of response quantities such as story drift or inelastically dissipated energy. Sophisticated optimization algorithms are utilized to solve the resulting mathematical programming problem. The frame design method is illustrated through application to an example 4-story, 3-bay, moment-resisting steel frame. The method's practicality and reliability for this example problem are assessed.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-81-20.pdf (4 MB)