International Seismic Zone Tabulation Proposed by the 1997 UBC Code: Observations for Mexico

The Uniform Building Code (UBC) is perhaps one of the most advanced seismic codes worldwide. The 1997 version of the Uniform Building Code (UBC-97) has important modifications with respect to previous versions, among other changes, the introduction of structural overstrength, redundancy and reliability factors for the design of structural elements. In addition, the UBC-97 code revises seismic zoning for areas outside the United States under Division III, Section 1653. In fact, practically the entire world is zoned by the UBC-97 under this section, and many practicing engineers worldwide may feel confident to use the UBC code for the design of civil structures in countries other than the United States, particularly because it is written in this section that “Note: This division has been revised in its entirety”. This paper discusses whether or not Section 1653 of the UBC-97 code has any justification for Mexico, by comparing the UBC design criteria with the criteria established by ruling Mexican codes. According to Mexican authorities, only the referenced Mexican building codes should be used for the design of civil structures in Mexico, so the UBC-97 cannot be used for the seismic design of civil structures in Mexico legally.