OUTLINE OF EARTHQUAKE PROVISIONS IN THE RECENTLY REVISED JAPANESE BUILDING CODE.

Abstract

The revised building code of Japan, to become effective in June, 1981, is reviewed. It features a two-phase design for earthquakes. The first phase design is for medium earthquake motions, and this is basically the unchanged traditional seismic design. The new second phase design is intended to give protection to buildings in case of severe ground shaking. It requires checking of several aspects of the building that has been proportioned by the first phase design. These include storey drift, vertical stiffness distribution, horizontal accentricity and ultimate lateral load carrying capacity. Both phases of the design are reviewed in detail, with some numerical examples to illustrate the design procedure. A comparison with New Zealand seismic design loadings is also made.