Re-Identification of the Quality of Formation of Pineapple Dome (Ourchin)with an Emphasize on Geometrical and Architectural Structure

Dealing with the methods of constructing a dome, knowing its various types, studying its structural performance, methods of drawing, styles, executive methods and related issue to it has always been preoccupations of Iranian architects. Amid these, the architecture of pineapple dome which is one of the features of mausoleum buildings in the southern part of Iran has not been given sufficient attention and there is a little data on it in the history of Iranian architecture. In this research the semantic and etymological meaning of pineapple dome has been discussed and the origin of the architecture of this type of dome dates back to Saljuk period. Then the geometrical relations among its saddles has been analyzed and various kinds of this dome including Koukabi(star dome) and polygon have been drawn. Studying the species of present samples in Iran and Iraq, noticeable points were evaluated on geometrical relations, height, form of dome and number of its saddles. Factors such as the performance of apex, method of construction, cover of dome, method of distribution of weight in the structure of the dome have been specified. Lastly, we will come to this conclusion that the main reason for its existence is a symbolic performance and not a pure religious symbol, because independently or in association and integration with religious spaces in the course of time, it has had an effective and pragmatic role. The research methodology in this research is of descriptive-analytical research type. Also based on need, in different parts of research, comparative analysis, retrospective studies and field work studies have been used. based on possibilities and opportunities, limits and threats, the article presents certain strategies to recreate sustainability.