Title: Formulation of a Conceptual Seismic Code
Author(s): V. V. Bertero and R. D. Bertero
Publication: Symposium Paper
Appears on pages(s): 255-288
Keywords: ductility; earthquake-resistant structures; hinges (structural); loads (forces); standards; stiffness; structural design; Design
A new conceptual code format has been developed for earthquake- resistant design (EQ-RD) of buildings. It consists of guidelines for conceptual overall design of entire building systems and a conceptual methodology for numerical EQ-RD of building systems in compliance with the worldwide accepted EQ-RD philosophy and based on energy concepts, fundamental principles of structural dynamics, mechanical behavior of entire building facilities, and comprehensive design. The numerical EQ-RD methodology considers the desired seismic performance of the entire building system explicitly from the beginning of the EQ-RD process and concludes by evaluating whether such performance would be achieved. A discussion of the main aspects and problems involved in the preliminary numerical EQ-RD procedure is presented in this paper. Main results from its application to at 30-story reinforced concrete space-frame building are discussed and compared to results from analysis of the performance of the same building designed according to 1991 UBC, showing the weakness of present UBC seismic regulations when applied to tall buildings, particularly regarding performance under service level EQ ground motions. The main advantage of the proposed conceptual methodology is that uncertain quantifications of its concepts can evolve without changing the format of the codified methodology as new and more reliable data are acquired.