A historical experience of local seismic proof shelters in Quchan-northeast of Iran

Despite the utilization of several earthquake resistant traditional techniques in Iranian architecture throughout the centuries, the high seismic vulnerability of Iranian vernacular constructions is obvious. One of the latest innovations in building earthquake-proof emergency dwellings, prior to introducing the modern seismic design codes, took place during the successive destructive earthquakes of 1871, 1893 and 1895 in Quchan, located in northeast of Iran. These new shelters withstood shocks successfully during the 1893 and 1895 quakes and were in use for at least the next 30 years. Therefore, this local effort of building earthquake-proof constructions will be introduced in this paper not only as an intangible heritage of the regional knowledge, but also as a successful experience in building earthquake resistant installations. In this article, the process of innovation of these new shelters, their specific earthquake resistant features which did not have any peers in shape in the history of the construction in the region, their evolution and finally extinction is described. Furthermore, the paper comprehensively focuses on describing the capability of these shelters in comparison with similar geometrical forms of construction to indicate how local people chose the best shape alternative based on the following three factors: seismic resistance, ease of built and the amount of spatial similarity with previous local buildings.