Calculation of equivalent lateral seismic forces based on ASCE 7-02 and KTP 2-89

Abstract

This paper describes the equivalent lateral force procedure according KTP 2-89 andASCE 7-02, and it gives light upon the differences between these two standards. KTP 2-89has not been updated for a long time now, as of year 1989. Being aware of the developmentand changes that other standards have achieved in the past decades, it is of major interest tohave an understanding of the today differences. The equivalent lateral seismic forceprocedure, is one way of representing the seismic effect on the building during the structuralanalysis and design stage. The lateral earthquake design force at the base and the lateral forcedistribution along the building height depend on different modification factors and designspectra, which are different for each standard and require a lot of calculations. In this context,this paper presents a spreadsheet which facilitates the calculation of base shear, distributedlateral force along the building height, and the overturning moment, both based on KTP andASCE 7-02. By describing a case study of a building, some quantitative differences betweenthe two standards are shown.