Typology and geometrical and Structural Analysis of Yazdi-Bandi in Iranian Architecture

In this research, Yazdi Bandi Domes considers as a one of the roof ornaments in Iranian traditional Architecture that in local expression called “Karbandi”. Karbandi is a expression that refer all of the three dimension works in Architecture motifs of the roofs like “Muqarnas”, “ Rasmi Bandi” , “ Kase Sazi “ and “Yazdi Bandi “. The aim of the paper is to present a New Identification by categorizing and geometrical and structural analysis of Yazdi Bandi. The authors observed and surveyed the many cases of Yazdi bandi in different cities and monuments. Specially Historical Iranian cities like Isfahan , Yazd , Kerman and Natanz and it observed in many types of the building like Mosques , Madrassa, Bazars and others. Also it covers many historical eras from the Seljuk’s Empire in 5th century (A.H) to Qajars dynasty in 19th century. To reach the aims, first authors search for the origins of this architecture element in the primary sample of the ribbed vaults in Isfahan specially the great mosque of Isfahan. And then by categorizing the observed cases, attempts to analysis the geometry and structure specification of the Yazdi Bandi. Therefore, the existence of a determined Geometric units named “ Sine Fakhri “ is held in common in all of the cases, so it could be consider as a most significant geometric elements of Yazdi-Bandi. After survey of Yazdi Bandi cases by authors, this elements of Iranian architecture can be categorize in two types. First of them refers to kind of Yazdi Bandi that most of the geometric and structural specifications is resembles to Rasmi Bandi. This type of Yazdi bandi seems has been created by mutation of Rasmi Bandi with fragmentation of geometric units to Yazdi Banid geometry. This types of Yazdi divided in two groups. In the first group, there is no Horizonal elements in Structural form but in the second, there is a horizontal star shapes polygon that called “ Takht “. Because of horizontal shape of this elements, this types of Yazdi Bandi cannot consider as a load bearing structure. Among the cases observed, this types of Yazdi Bandi has the most redundancy between other types. This types of Yazdi can be observed in many monuments like historical houses specially in Kashan and Kerman. Also there is anothers types of Yazdi Bandi that could be observed in some historical monuments specially in Isfahan, In “ Chahar-Bagh Madrassa “ or “ Naghe Jahan square “. This types of Yazdi Bandis unlike other types, the geometric and structural specifications of them likewise construction techniques are most resemble to Muqarnas specifications. By geometric analysis and survey in drawing methods as well as two and three geometry dimensional analysis, it can be suggested that this kind of Yazdi Bandi has been created by mutation and evolution of Muqarnas specifications. The research methods of this paper consist of direct survey of case studies and also utilize of resources and documents in library