SEISMIC HAZARD ANALYSIS AND DESIGN LOADS*

This article briefly reviews the seismic design load and zoning scheme proposed by the NZNSEE Bridge Study Group and discusses subsequent work in improving the underlying estimates of New Zealand seismic hazard. The loading scheme, published in 1 980, was based on contemporary knowledge of seismic hazard in New Zealand and was innovative in its format which was chosen to give the designer flexibility in selecting the degree of ductility built into the structure, and the return period of the design motions.