خلاصة:
مقرنس، هنری پرکاربرد در معماری دوره اسلامی است که از اندلس و مغرب تا هند مشاهده میشود. از لحاظ گستره و تعداد در ایران کنونی مقرنسهای پرشماری با طرحهای گوناگون مشاهده میشود. هر چند این ساختار با کلیات مشابه در سراسر جهان اسلام نیز رویت میگردد. در نگاه اول مشابهتهای زیادی بین مقرنسهای مغرب جهان اسلام شامل مصر و شمال افریقا و آناتولی و شامات) و مقرنسهای ایرانی دیده میشود، اما در بررسی اصول هندسی پیادهسازی مقرنس و همچنین اصول اساسی اجزا یا آلتهای سازنده آن تفاوتی آشکار دیده میشود. این مقاله میکوشد با بررسی مقرنس، از طراحی پلان تا مدل سهبعدی، تفاوتهای ایجادشده در نمای یک نیمه گنبد مقرنس در چفد نمای ایوان را مشخص سازد و از این طریق تفاوت مقرنس ایرانی را با مقرنسهای غرب جهان اسلام نشان دهد. اینجا دو علت مهم این تفاوت مشخص شده است: یکی اصل قرار دادن واحدهای شکلدهنده مقرنس، مانند جنس آلات مقرنس، و دیگری قدرت هندسی معماران ایرانی در تطبیق هندسه پایه مقرنس با چفد نمای ایوان.
Muqarnas is one of the most popular decorative forms in Islamic architecture, from Andalusia and Morocco to India. There are numerous cases of muqarnas with a diversity of designs all around the present-day Iran. Although muqarnases all around the Islamic world (including Iran, along with Egypt, North Africa, the Levant, and the Asia Minor) look generally the same and carry a similar structure, studying their geometric principles of construction and building elements shows distinct differences. We are aiming to show the displacement of elevation of a muqarnas in a semi-dome from the arch of a semi-dome in the façade of an iwan through studying the construction of it from planar design to a 3D model; and thus underline the differences between muqarnases in Iran and those in the western Islamic world. What this paper investigates is the coincidence of a muqarnas and the arch of an iwan. A muqarnas is usually designed in plan, and then transformed into a 3D model by using specific rules. Since these rules are distinct, when a muqarnas is designed in plan, the 3D model and thus its elevation is already determined. In “muqarnas domes”, plan of the muqarnas coincides perfectly on plan of the dome and the elevation is not visible. But in an iwan, basically, the elevation of muqarnas should never fit the arch. Unlike what we are accustomed to see, the elevation of a muqarnas should actually look like a set of small arches, one on the top of the other. Clearly, this shape is different from the arch of iwan. The elevation of a muqarnas is not only indented, but its rising trend is also different from that of an iwan’s arch in most cases. This would create a vacant space between the arch and the elevation of the muqarnas. Several solutions have been developed by Islamic architects around the world. These solutions will be compared here and the characteristics of the Iranian one will be described. The Egyptian and the Anatolian solutions are classified into 4 groups. They tried to match the elevation of muqarnas to that of iwan. But these muqarnases, being made of stone elements, are more adhered to the shapes of their elements, thus the elevation still looks indented. Comparing these solutions with the Iranian ones, in which the muqarnas fits perfectly well into the arch of iwan, indicates that Iranian architects had the capability and courage to conceive the 3D model and its elevation along with its plan, especially in entrances. This paper demonstrates two main reasons for these differences. First reason is the mainstreaming muqarnas elements, considering their material, in the design. Stone muqarnases are designed through repetition of some certain elements, thus they are limited in creating some special forms (i.e. arch) in the elevation. Unlike these muqarnases, Iranian ones are designed on the basis of level lines (“Pa”s of muqarnas) and constructed separately in each level. This removes the previously mentioned limitation. The Iranian architects in this way have prioritized the perfection of the elevation over the ease of construction. The second reason for those differences is the Iranian architects’ geometric perception of coinciding a muqarnas plan on the elevation of an iwan. These architects have tried to solve the mismatch through a geometrical solution. To do so, they determine intersection points between the arch of iwan and the level planes of the muqarnas, and then they manipulate muqarnas elements to match the desired form in the façade of mosques’ iwans or their entrances.