دروازه عصر برنز سه قوسی در تل دان؛ تحقیقات ساختاری یک سایت باستان شناسی فوق العاده

The three sun-dried mud–brick arches of Tel Dan spanning the gatehouse passageway are the world’s oldest known complete and free-standing monumental ‘true’ arches made of this material. This gatehouse is dated to the mid-18th century BC, and stands today more than 7 m high. The city gate was excavated during the 1978–1985 seasons, revealing a vast gatehouse in a remarkable state of preservation. All its three arches were soundly constructed in three concentric radial courses. The archway owes its extraordinary state of conservation to the fact it was filled and buried by the inhabitants after only some years of use. The paper presents the structural and technical investigation of the performance and failure of this unique historic building form, putting it in an archaeological context and discusses the research methods and findings giving a picture of the strength and limitations of the mud–brick arches – extraordinary representatives of historic building technologies. The article puts forward a hypothesis for the construction technique, which could provide a perception of the architectural development of arches and an aspect of the dynamic of learning – in progress in the building cultures.