چکیده:
Changing the square into the circle in the structure of dome chambers was a main problem in Iranian architecture.The solution to this problem has led to the formation and creation of capable methods and techniques in the structureof a part of dome chambers that changes square chamber below into the round dome above it. This phenomenonhas been considered as “the zone of transition” (transitional zone) in many studies on Iranian architectural history,but it has been less seriously studied in a strict sense as an important independent part. On the other hand, the waysquare chamber corners corbel has made different forms of structures that is called “squinch”. The four squinchestogether with the middle parts between them organize the mentioned zone (zone of transition). In some studies, thezone of transition has been described considering the load-bearing elements of corbelled form of squinches. Someexperts have indicated different forms of squinches such as “stalactite squinch”, “conical squinch”, “trie-lobedsquinch”,”squinch net” and some others have talked about it considering materials, ornaments and constructionalstyles. Although these considerations present some aspects of transitional zone such as historic, structure andform, it rarely has been explained as a complete evolution and clear classification. Geometry, as the essence andnature of this process (changing square into the circle), is certainly a decisive item. Therefore, this research is goingto explain the zone of transition from the view point of geometry, considering the geometrical system betweensquare and circle that leads to a regular polygon as the base of dome. According to this geometrical approach, thearticle first reviews two old methods used before Seljuk era and then, explains the elegant form of Seljuk zones oftransition originated in Nezamolmolk dome of Isfahan, as the most fashionable pattern existing in Iran for morethan three centuries. In the next phase, which is the context of this research, the transitional zone of Gonbad-esorkh is explained as a novel form leading to a hex decagon. Although the dominant pattern also eventuates ahex decagon, the case of Gonbad-e sorkh, as an authentic Seljukian monument, does not follow it and presents adifferent solution. The difference between these two solutions is presented by a comparative analogy. First, theprocess of changing square into octagon and then hexadecagon in Seljukian fashionable pattern is described. Then,it is compared with the process of changing square into hexadecagon in Gonbad-e sorkh. By this comparison,
the paper finally presents the zone of transition of Gonbad-e sorkh as a “shortcut pattern” of a novel geometricalarrangement of transitional elements.
خلاصه ماشینی:
"Explanation of Geometrical System of zone of transition in Gonbad-e Sorkh in Comparison with Common Pattern of Seljuk’s Zone of Transition* Abstract Hojat Golchin** Ahmad Salehi Kakhki*** Abdollah Jabalameli*** Changing the square into the circle in the structure of dome chambers was a main problem in Iranian architecture.
*. The present study is extracted from PhD thesis on the restoration of historical buildings by Hojat Golchin with the supervision of Dr. Ahmad Salehi Kakhki and Dr. Abdollah Jabalameli, entitled "explanation of geometrical system resulting in circle in the transitional zone of Iranian dome chambers and classification of their evolution", in the faculty of restoration and protection of Isfahan Art University.
9 The Scientific Journal of NAZAR research center (Nrc) for Art, Architecture & Urbanism Introduction and problem statement The process of changing square into the circle in Iranian dome chambers and the how of this process is a problem that has created many architectural forms and techniques in the structure of domes’ zone of transition over the centuries of trial and error.
The second step of this process, which should be really considered as a turning point in the formation of a precise geometric system, is the brilliant achievement of the zone of transition in "Dome of Amir Ismail Samani" in Bukhara, where eight identical Ribes alternatively cover the corners of the dome-shaped room, thus providing a zone The Scientific Journal of NAZAR research center (Nrc) for Art, Architecture & Urbanism 81 Nazar, 14 (57):75-84 (View the image of this page) Fig. 1."