A. Danaeinia, S. S. Korsavi,
Volume 27, Issue 1 (6-2017)
Abstract
Little has been written about the structural behavior of conical shells, while conical shells’ construction techniques due to the high rise and small span has always required special attention throughout the history of Islamic architecture. This paper aims to examine how conical shells bear weight loads and resist against bending through a qualitative analysis. After proving that ‘rise/span’ ratio strongly affects weight loads and bending in external shells, the main question of the paper is “what construction techniques architects adopted to carry weight loads, and how these techniques differed in domes with various ‘rise/span’ ratios”. To find out about paper’s main question, a qualitative approach for structural analysis has been adopted. First, architectural maps and dimensions of six cases were documented, and then, according to the documentation, some ratios and parameters have been defined to find their probable correlation with ‘rise/span’ ratio. Results show that to restrain weight loads in external shell, design of stiffeners and thickness of the conical shell play a crucial role to keep structure balanced. According to the results, ‘rise/span’ ratio has a positive correlation with ‘thickness/span’, ‘height of stiffeners/span’, ‘stiffeners’ sectional area/span’, ‘gradual decrease of thickness’ and “number of stiffeners/ number of flat planes”. In contrast, ‘Rise/span’ ratio does not have any meaningful relationship with ‘stiffeners’ end point’ and ‘struts’ end point’, and has a negative correlation with “the number of flat plains.
Ahmad Danaeinia, Majid Heydari Dehcheshmeh, Soroush Rahman,
Volume 30, Issue 1 (6-2020)
Abstract
In the architecture of the mosque, the light entering into the dome is a functional necessity and due to the structure, the weight of the dome and its one or more shells has caused limitations in any kind of skylights to be encumbered. The research main question is that due to the mechanism of the dome parts, how the creation and the entering of skylights to the dome were done. The research method is a combination of both quantitative and qualitative methods. Initially, based on library studies, researcher's opinions were investigated and by analyzing 14 types of mosques from the Seljuk to the Qajar era in Iran, analyzes on how to create skylights through the dome were accomplished. This research answer two essential questions which are what principles had been followed for locating skylight in the dome? Moreover, how did light enter through the dome, in one-shell and two-shell domes? The findings show that in the one-shell domes, the position of the skylight is variable. In detached two-shell domes, the skylights are placed merely in 45° areas and are not limited in terms of numbers. Conclusions state that one-shell domes had a restriction to the number of skylights, in comparison to the two-shell domes. In detached two-shell domes, lighting was possible until the 22.5° area and considering no limitations, there has been no skylight in the area between 67.5° to 90° apart from a few exceptions.
