SEISMIC CODE RELATED DEVELOPMENTS IN THE UNITED STATES

This paper traces the evolution of U.S. seismic codes over more than seventy years and discusses current developments that will doubtless influence codes around the world. Although one might have expected the development of seismic building regulations following the San Francisco earthquake of ۱۹۰۶, it did not occur. Earnest efforts in that direction did not begin until after the Santa Barbara earthquake of ۱۹۲۵. The Pacific Coast wildingOfficials Conference (which later became the International Conference of Building Officials) published in ۱۹۲۷ the first seismic design provisions in any of the major regional American building codes, in its Uniform Building Code [۱], first edition. The provisions were contained only in an appendix and were not mandatory. Significant changes were made in the ۱۹۳۵ edition of the UBC following the ۱۹۳۳ Long Beach earthquake, and again in the ۱۹۴۹ edition of the UBC.