Recent severe earthquakes have selectively damaged or destroyed many large modern buildings. The destructive earthquake s at Caracas in Venezuela, July 1967, near Tokachi-oki in northern Japan, May 1968, and the two earthquakes at Manila in the Philippines, August 1968 and April 1970, have all highlighted important factors which should be considered during the earthquake-resistant design of buildings. Reports on these earthquakes which directly supplement this paper are listed in the references.