The Earthquake Engineering Online Archive

Optimum design of earthquake-resistant shear buildings

Ray, Debabrata; Pister, Karl S.; Chopra, Anil K.

UCB/EERC-74/03, Earthquake Engineering Research Center, University of California, Berkeley, 1974-01, 88 pages (620/R29/1974)

This report is the first of a series of studies concerned with identification and simulation of the response of multistory framed buildings as a function of design variables and earthquake ground motion. A methodology is developed via optimization theory in which concepts of objective function, behavioral constraints and system dynamics are given a mathematical structure upon which optimal synthetic design can be based. After developing a general background for a well-posed problem of optimal design, application to one-bay, multistory, unbraced frames is discussed to illustrate the methodology. Minimum volume of column sections is taken as the objective, along with the constraint that the structure should respond elastically with limited relative story drifts under moderate earthquakes. System dynamics appropriate to a shear-type building frame are adopted along with ground motion characterized by standard pseudo-velocity response spectra. Optimization of both a 2-story and an 8-story shear building is carried out by means of a computer program based on the Polak version of the method of feasible directions. Results of the study establish the feasibility of the optimum synthetic design procedure, although caution must be exercized in handling the somewhat sophisticated method of optimization. The report concludes with a brief note on work currently in progress, aimed at enlarging the problem class that can be studied effectively by optimization theory.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-74-03.pdf (33 MB)