|Description of work:||Restoration research|
|Investor:||Ministry of Culture of the Regional Government of Kurdistan, Iraq|
|Contractor:||GEMA ART GROUP a.s.|
Erbil, originally Sumerian and Assyrian city is located in the foothills of the eastern Iraqi mountains is believed to be the oldest permanently inhabited city in the world. Choli minaret is dated to the Atabag period and was built by ruler of Erbil Muzaffar al-Din Kukburi (1168-1233) brother in law of well known Salahaddin. The structure was built from low burnt bricks using gypsum based renders and mortars. Due to the long term effect of deterioration, the essential part of the architecture has disappeared and thus the leaning minaret is the last survival of the past mosque.
The shape of the minaret covers the lower, seven-angle section of about 12 m high and upper broken cylindrical part of approximately 24 m high. The body shelters a double spiral staircase. A large extent of precious historic fragments of renderings and embossments were identified in the lower part of the object. Particularly large scale findings of Egyptian blue ceramic decoration in niches are considered as upmost important. All fragments of ceramic, brick and stucco decorations were seriously affected by weathering and mechanical damages.
Probably due to the sudden movement of the geological underground layers the whole structure lost its upper part. Subsequent long term effects of leaking rain water and the intensive weathering made the structure unstable and the surface of the minaret heavily deteriorated. There was also serious loss of joint material and decrease of binding media in the joint mortar.
The general assessment of the whole monument had carried out before the conservation and stabilization of the minaret started. The research was provided in four phases: taking samples (03/2006), ground water study (08/2006) and site research covered photogrammetry documentation, 3D visualization and comprehensive geo-physical survey of the surroundings (incl. Micro-gravimetry, Shallow Refraction Seismology, Resistance methods and Seismic 3D/2D Tomography), comprehensive material research, geological survey and static measurements. General seismic study was carried out to identify the origin of inclination and reasons of the historic loss of the upper part of the minaret.
The general assessment was carried out based on the contract with the Ministry of Culture of the Kurdistan Regional Government in Iraq and became the base for preparation of further conservation and stabilization project.