In October 31st, 1983, an local earthquake of Magnitude 6.3 hit Tottori Prefecture, western area in Japan. The maximum seismic intensity of this earthquake was IV in the JMA Seismic Intensity Scale which corresponds to approximately VI in the Modified-Mercalli Intensity Scale.

Slight damage of buildings due to this earthquake was reported in some restricted areas. However a three-story reinforced concrete city office building in Kurayoshi City, which is located within ten kilometers from the epicenter, was extremely damaged at the 2nd story.

From correlation between crack distribution pattern and eccentrically arranged resisting walls in the plan, it was estimated that very large torsional response was produced during the earthquake. In this paper, damage features are first introduced, and next, results of analytical studies, which include an application of the Aseismic Diagnosis Method used in Japan and translational-torsional earthquake response analyses,are summarized and discussed.

^*1 Director, Research Planning and Information Department,
^*2 Head, Large Scale Structure Testing Division, Production Department,
^*3 Assistant Research Engineer, Structural Dynamics Division, Structure Engineering Department, Building Research Institute, Ministry of Con-struction.