Structural Typology of Karbandi and Rasmibandi in Persian Architecture based on the Place and Method of Usage

The so-called “Karbandi” and “Rasmibandi” are two kinds of vault covering elements based on Islamic star geometry, which are of the most common patterns in the restored projects and new buildings, including the Haj Mohammad Qoli Timche in Tabriz historic bazaar, the Mausoleum of Omar Khayyam in Nishapur, and others. These patterns are created by intersecting several rib vaults based on totally strict mathematical and structural techniques. Despite the importance of Karbandi and Rasmibandi in Persian architecture, there are plethora of contradictions and disagree ments between workmen and researchers for deter mining and classification of various types of Karbandi and Rasmibandi. Therefore, the solidarity of previous statements and papers are diminished. Accordingly, the major question is as: what are the differences between various types of Karbandi and Rasmibandi based on their place and method of usage. The pur pose of this paper is the clarification of Karbandi and Rasmibandi types and to find the similarities and dif ferences between them. This study is a basic theoreti cal research and the research methodology used is analytic-descriptive, which relies on historical sources, historical documents, texts and images in historical periods and constructed samples. The paper is pre sented in two major sections. The first section is re lated to the scrutiny and comparison of previous works and attempts to determine the specific defini tions of Karbandi and Rasmibandi concepts. As a con sequence, the position of Kars in either major or sec ondary vaults cannot be used as criteria to distinguish Karbandi from Rasmibandi. The Karbandi as coverture can be used in both covertures of major vaults and coverture of secondary vaults, whilst, Rasmibandi can exclusively be used beneath major vaults. The most important difference between the major and second ary vaults is the kind of their load bearing mechanism. In the case of major vaults, the burden of both two clusters, dead loads and live loads, is by means of Karbandi. However, in the secondary vaults, Karbandi usually bears its own dead loads. Moreover, the Nim kar (semi-work) can be categorized in two Karbandi and Rasmibandi groups based on their performance and load bearing behavior. Karbandi has a rib vault of load bearings elements, whilst, Rasmibandi is con structed in dependence with upper vaults.
In the second section of this paper, the applica tions of different Karbandi and Rasmibandi types are investigated and their key points are highlighted by considering the findings of the previous section. The results indicate that, not only can Karbandi be used in the applications of coverture positions, but it also has non-coverture uses. Karbandi is someties used as either “Chapireh-Sazi” or in facade of buildings. In the case of “Chapireh-Sazi”, Karbandi is usually used by means of “Shekanj” and “Gosheh-Sazi”. In the case of Gosheh-Sazi, the transition is usually done without any height increase of dome. Thus, “Chanbare” is not created beneath the dome and the height of Cha pireh-Sazi remains unchanged. Finally, a comprehen sive classification of various types of Karbandi and Rasmibandi was presented based on usage place, constructional and form-related features, application, structural function, and material of rib vaults.