Seismic Response of Buildings Designed by Code for Different Earthquake Intensities. Optimum Seismic Protection and Building Damage Statistics,Report Number 4,

摘要

Seismic analyses have been made for five multi-story buildings of different types,each designed for five different levels of protection under the UBC Code. Both elastic and inelastic analyses have been made. The former is based directly upon a response spectrum,and the latter is based upon an artificial time-history input generated from the same response spectrum. For the buildings investigated,it is concluded that,for both elastic and inelastic response,the average peak interstory displacement agrees very closely with that predicted by the first-mode elastic response. The elastic limit earthquake and the average maximum ductility ratio bear an approximate linear relationship with the ratio of first-mode elastic base shear to bottom story resistance. It is further concluded that increasing the equivalent static lateral design force,as in conventional code procedures,does not appreciably reduce the interstory displacements. It does,however,increase the elastic limit earthquake and,to a lesser extent,decrease the maximum ductility ratio for a larger earthquake.