SEISMIC CODE ANALYSIS OF BUILDINGS WITHOUT LOCATING CENTERS OF RIGIDITY

Static force procedures of most building codes require that the latera l earthquake force at each floor level of an asymmetric-plan building be applied eccentrically from the centers of rigidity. To implement su ch procedures, it seemed necessary in the past to determine the locati ons of the centers of rigidity, an often confusing and cumbersome proc ess. This paper presents a new approach for code lateral force analysi s of asymmetric-plan buildings without locating the centers of rigidit y. This procedure combines the results from three static analyses, whi ch can be implemented directly on most commercially available computer programs for analysis of multistory buidings. The work presented in t his paper should dispel the long-held view that locations of the cente rs of rigidity must be determined to implement the code procedure, the reby removing one of the major difficulties in building analysis.