M. R. MAHERI - Research Fellow/Senior Engineer, WS Atkins Engineering Sciences, Epsom, U.K

The behaviour of traditional masonry buildings common throughout Iran during the Manjil earthquake of June ۱۹۹۰ proved, as observed during many previous earthquakes in Iran, the vulnerability of these buildings to seismic loading. In many other respect, however, the Manjil earthquake may be considered different to the past earthquakes, in that it struck a densely populated and relatively industrialised part of the country, affecting a large number of engineered and semi engineered buildings and other structures. As a result, perhaps for the first time, the performance of such code recommended measures as concrete ring-beams, the engineered version of steel I-beam, jack-arch roofing system and the more recent concrete beam-block system in small buildings, as well as the behaviour of taller steel and concrete framed buildings could be observed in the field. In this article, certain aspects of the response of such structural elements and buildings are discussed