Structural Behavior, Geometric, and Constructive Analysis of the Medieval Wooden Dome in the Hall of Ambassadors of the Alcazar of Seville

Abstract

The wooden dome that covers the Hall of Ambassadors of the Alcazar of Seville (1427 AD) can be considered an exceptional architectural and constructive element in which visible ornamentation and underlying structure are inextricably linked. This article proposes a methodological approach integrating different disciplines (engineering, architecture, and history) to discern comprehensively the genesis and the in-depth constructive and structural performance of this outstanding architectural heritage. Thus, based on historical references on the construction of wooden domes together with the knowledge that the carpentry guild applied at that time, a detailed geometric and constructive analysis of the dome has enabled us to establish that its construction must have been carried out through the prefabrication of sectors. In addition, a structural model has been generated, with which, through various hypotheses, using a nonlinear finite-element analysis its mechanical behavior can be understood. The profusion of noggings, which follow the strict geometry derived from patterns of 10-point stars, plays a fundamental role in the stability and resistance of the set. Furthermore, it has been verified that an additional roof structure should always have been located over the dome and the tie rod bracing, made of steel nowadays, should always have existed and is located in its most optimal position.