Randolph Langenbach - International Building Conservation Consultant

The Arg-e Bam is a remarkable example of earthen architecture and construction that was heavily damaged in the Bam, Iran earthquake of ۲۶ December ۲۰۰۳. This paper presents the hypothesis that the collapse of the walls was caused largely by a combination of the effects of (۱) the additive changes made to the walls, particularly in recent restorations resulting in variations in the density and response to vibrations of different layers of unfired earth construction in the walls, and (۲) extensive damage from termites and loss of the cohesion of the clay from degradation and excessive drying out, all of which interacted with the earthquake vibrations of unusually high frequency in such a way that many walls effectively burst from the subsidence of their clay internal cores. Concern is raised about the possibility of similar risks to other earthen monumental structures from future earthquakes.

Earthen Architecture, Earthen Construction, Adobe, Khesht, Cob, Chineh, termites, Soil Dynamics, Earthquake Vibration Frequency, Vertical Earthquake Accelerations, Bam Citadel, Arg-e Bam, Bam earthquake, Iran