Reflection of Seismic Risk in the Honolulu Building Code

Abstract

This report deals with an issue concerning the seismic risk zone to which the island of Oahu should be assigned in the Uniform Building Code (UBC) and the building code of the City and County of Honolulu. At present the assignment is to UBC zone 1. More than a decade ago, however, the adequacy of the risk reflected by this assignment was challenged, the challengers claiming initially that the assignment should be to zone 2 and more recently recommending assignment to zone 3. In recognition of the challenge, the Natural Hazards Group of the University of Hawaii established in 1985 a Task Force to investigate the appropriateness of the risk zone assignment. The investigation was undertaken by the author of this report as a member of the Task Force. The methods used in the investigation are summarized and the conclusions reached are presented in this report, which is the last of several prepared by the author for the use of the Task Force as a whole.