سیر تحول ویژگی‌های فضایی و ساختاری گنبد در تاریخ معماری ایران

One of the most important and prominent elements of Iranian architecture is the roofing system, particularly domes. The construction of domes in Iran has ancient roots dating back to the pre-Islamic era and experienced remarkable progress during the Islamic periods. Geometry, mathematics, and the emergence of new tools throughout history have had a direct impact on the evolution of the form, structure, and construction of domes. This article aims to examine the historical evolution of the dome as a key element of Iranian architecture, its position in Islamic architecture, and the classification of various types of domes and arches. It analyzes the spatial and structural characteristics of this element. Domes from the Parthian period were generally circular and of the ribbed type (mazeh-dar), with a height greater than the radius of the base. In the Sasanian period, the arches included various types such as horseshoe, semi-circular (hilochiin), ribbed, Sasanian elliptical, and egg-shaped arches, which lacked pointed tips and possessed high load-bearing capacity. In the early Islamic centuries, slow and fast horseshoe arches, followed by pointed arches, became prevalent. In later periods, especially during the Timurid and Safavid eras, pointed load-bearing and decorative pointed arches were commonly used. The findings of the study indicate that developments in geometry and mathematics have been the main factors in the advancement or decline of the structural characteristics of domes in the history of Iranian architecture and can serve as a foundation for future research in this field.