The New York City Seismic Code: Local Law 17/95

Background: The 1982 edition of the ANSI A58.1 Minimum Design Loads in Buildings and Other Structures (ANSI, 1982) included a new seismic design section, modeled after the UBC and ATC 3-06, which placed New York City in Seismic Zone 2 (vs. 4 for California). This would in turn have triggered the application of the ductile design provisions of the ACI-318 code for concrete design. The New York City Building Commissioner asked the New York Association of Consulting Engineers (NYACE) to review the matter. The initial response, in the summer of 1984, was to recommend that such requirements be omitted. However, after some discussion, it was decided that a group of seismologists and engineers review the issues and advise NYACE. The Committee’s conclusions have been reported above. Following this, the NYACE Board unanimously recommended to the Commissioner, in June 1987, that seismic design be mandated in New York City, and that these should follow the 1988 UBC (UBC, 1973). At the same time (1986), the National Center for Earthquake Engineering Research (NCEER) was established in Buffalo, New York. Several conferences were organized as a result (Jacob et al., 1987; Jacob and Turkstra, 1989) which addressed the particular issues of seismic hazard and design in the

eastern U.S. Following these, the Commissioner appointed, in April 1989, a Seismic Code Committee to draft seismic code provisions for New York City. This Committee included engineers, seismologists, and representatives of the building industries and real estate community. The Seismic Code Committee voted unanimously to submit its final report to the Commissioner in early 1991, and the report was submitted on 18 April 1991.