Encountering mudbrick structures poses more fear and concern for restorers than excitement due to the challenges and uncertainties in protecting them with logical measures. Preserving such works, which often blur the line between passion and intellect, emotion and reason, while requiring constant care, can be unproductive and cause unsatisfactory outcomes. This is primarily because the restoration community, for various reasons, has been slower in responding to environmental factors and sometimes irrational human behaviors. It is crucial to understand that conservation, in its most scientific sense, cannot thrive without proper attention, even in its simplest form. Experience has proven that mudbrick structures demand more maintenance and care than physical interventions. This study, conducted through fieldwork, library studies, and an objective environmental assessment, aims to address the gaps in protection and enhance the conservation of the ChoghaZanbil site against current and potential threats. Furthermore, it seeks to identify the challenges facing the complex’s progress and its role in this endeavor. The protection journey of the site, from initial threats to the inception of the international ChoghaZanbil project, underscores the importance of adopting flexible defensive strategies over rigid offensive approaches for greater success.
ChoghaZanbil, located in southwestern Khuzestan province, is a site situated approximately 40 kilometers southeast of the ancient city of Susa. The highest point of Chaghazanbil stands at around 90 meters above sea level. This religious urban complex, constructed in the 13th century BC, is known as the largest architectural masterpiece of the Middle Elamite period. It was commissioned by the influential king of the dynasty, Untash-Napirisha, and is dedicated to the Elamite deities, Napirisha and Inshushinak. The introduction of Chaghazanbil, once a part of the central government of Susa, to the modern world can be attributed to the activities of oil companies in the region. Aerial photographs taken for the discovery of oil fields in the area provided the first glimpse of the ancient city of Dur-Untash (ChoghaZanbil). Subsequently, the discovery of an inscribed brick in the site prompted the initial investigations conducted by "R. de Mecquenem" between 1936 and 1939. The year 1951 marked the commencement of the establishment of a management system of conservation for the site. The most extensive excavation efforts, spanning eleven years, were carried out under the supervision of "Ghirshman" from 1951 to 1962.
Mudbrick, brick, and mud mortars, plaster, and bitumen have been extensively utilized in the construction of Chaghazanbil. The primary material used was mudbrick, particularly in the construction of the central core of the buildings. The majority of the mudbricks were approximately 40 x 40 x 10 cm in size and were categorized into two groups: homogeneous (uniform clay structure) and heterogeneous (mixed with brick chips or brick powder). To protect the mudbrick core of the buildings from the region's humidity and heavy rains, a brick covering was applied around them. This was especially evident in the ziggurat, where the mudbrick structure was enveloped by a brick wall around two meters thick, secured using a traditional technique known as Hasht-o-Gir. However, the thickness of this brick wall was later reduced to the width of a single brick during renovations. Additionally, a variety of materials such as stone, wood, glass, stud, and ceramic pipes were used in a more limited capacity throughout the construction. Stones were used to cover certain stairs and create door sills, glass and clay studs served as decorative elements, ceramic pipes were utilized as gutters, wooden logs were employed for building doors, and tar-coated tree trunks were used to enhance the connection between the brick cover and the mudbrick core in the ziggurat. According to Ghirshman's reports, the coatings applied in the construction included cob, plaster, Sarooj consisting of quicklime, wood ash, and animal hair, as well as a red coating primarily made of iron oxide (Okhra), possibly mixed with oyster powder.
The protection management system for the ChoghaZanbil historical complex began with excavation protection from 1951 to 1962 under Ghirshman's supervision. The collection gained significant public attention when it was included in the World Heritage List in 1979. Efforts were made to conserve this historical collection until 1998, when the international project for the protection and restoration of ChoghaZanbil was formed. This joint project involved the country's cultural heritage organization, UNESCO, and the Japan Foundation. However, due to the discontinuation of conservation programs and incomplete projects, the effectiveness of conservation measures was compromised. During this period, one can witness deliberate protective actions being taken, alongside questionable and unconventional measures. Despite numerous protection and restoration efforts carried out on the architectural complex of the historical site of ChoghaZanbil since pervious excavations, they have generally been executed in a manner that preserves the historical integrity of the complex.
The majority of the activities conducted, evident in the form of façade details, have utilized historical materials; particularly noticeable in the ziggurat and the water reservoir. As for the two inner and outer walls, the temples, the remnants of residential structures, and even the royal tombs, the lack of significant efforts in their initial protection and restoration has allowed them to maintain the authenticity of their excavation period. However, the absence of consistent maintenance and a dedicated conservation plan has led to noticeable erosion. Overall, the history of conservation and restoration efforts at ChoghaZanbil serves as a stark reminder of the consequences of neglecting ongoing emergency protection and maintenance.
The threats facing the historical site of ChoghaZanbil can be categorized into three main branches: "Environment and Climate," "Form and Architectural Structure," and "Unconventional Encounters and Social Anomalies." Each branch presents specific cases that contribute to the overall analysis. This classification aids in identifying appropriate protective measures based on the severity and ranking of each problem, allowing for targeted solutions to address the issues within the site. Each level of threat necessitates the consideration of specific factors. The first case focuses on weather conditions and ecological elements such as plants and animals. The second case encompasses the construction characteristics of the building and materials used. Lastly, the third case highlights the impact of external behavioral factors on the vulnerability of the complex. The international project for the conservation and restoration of ChoghaZanbil has been initiated to mitigate weaknesses and reduce the severity of these threats. Upon examining the site, it becomes evident that a combination of climatic, physical, and intervention-related threats have affected ChoghaZanbil. Notably, seasonal heavy rains, extreme temperature fluctuations, the widespread presence of biological destructive factors (particularly termites), bank erosion, extreme wind and soil erosion pose the primary threats to the eco-climate.
In relation to the structural and physical threats, it is important to highlight the loss of the protective brick cover and the absence of a water disposal system. This is primarily due to the damage and blockage of the gutters, which has resulted in numerous instances of moisture-related damages. Additionally, the utilization of subpar soil for mudbrick production, along with incomplete soil preparation and mud processing, has compromised the quality of materials and heightened their risk factor. Furthermore, unconventional incidents and social abnormalities, such as unwarranted repairs in the past, unauthorized alterations to the architectural structure, disturbance of the ecological equilibrium within the complex's surroundings, and invasion of its historical and natural textures, pose further challenges for ChoghaZanbil. Generally, it can be asserted that ecological and climatic dangers are unavoidable yet manageable. The structural and physical perils associated with the incident at ChoghaZanbil can be rectified gradually, whereas the hazards stemming from irresponsible interactions and societal abnormalities necessitate a shift in the mindset of intellectuals at both individual and societal levels when it comes to safeguarding our values. These threats are prominent and all-encompassing, surpassing other dangers in terms of their diversity, and their resolution is bound to be more contentious.
Upon analyzing the state of ChoghaZanbil mudbrick architecture, it is evident that the process followed in constructing these architectural structures is technically successful and demonstrates a deliberate effort to create suitable conditions for integration with the surrounding environment. Merely focusing on the constructional characteristics of materials and potential damaging factors is insufficient for formulating a comprehensive conservation theory for these mudbrick structures. This is due to the fact that these remaining structures hold significant cultural value, embodying crucial aspects related to the civilization of Elam. The findings derived from field observations, environmental studies, examination of restoration and conservation records, assessment of care quality, and analysis of erosion processes in the historical region of ChoghaZanbil highlight the imperative for a significant transformation in the preparation and application methods of materials, particularly restoration mudbricks and protective cob. These materials exhibit the utmost sensitivity and are consumed on a large scale. Therefore, it is crucial to optimize and reinforce them by leveraging local resources. By ensuring precise handling and logical implementation, this approach can greatly ensure the consistency and durability of future protective measures.