An evaluation of the ductility reduction factor q in the 1976 regulations for the federal district of mexico

The reduction of the spectral accelerations to account for inelastic response of structures as given by the 1976 Regulations for the Federal District of Mexico is evaluated relative to the records obtained at the Secretaria de Communicaciones y Transportes (SCT) during the September 19, 1985 Mexico earthquake. It is concluded that the 1976 Regulations do not treat all types of structural systems equally. On a relative basis the 1976 Regulations provide less protection for those structures designed to larger values of ductility factors