[ Les remontées capillaires et la dégradation du rempart de Sidi Baba (Médina de Meknès) ]
Volume 14, Issue 3, February 2016, Pages 645–652
Rabha Ajakane1
1 Département de Géologie, Université Moulay Ismaïl, Meknès, Maroc
Original language: French
Copyright © 2016 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The city of Meknes is rich of various cultural heritages built between the XVIth and the XIXth centuries and notably it's most important ramparts (more than 40 km length). It was protected in 1995 by UNESCO as World Heritage. These earthen walls are between 1.20 to 3 m wide and 7 to 12 m high. The ramparts have been constructed in rammed earth according to a traditional Moroccan method. A detailed observation of the ramparts of the city revealed that they suffer from many different damages and they are in very bad state, some of them are disappeared. We noted that they show some alterations like fissures and more important detachment. The study of the origins of the alterations shows that they mainly depend on the environment, like the water impact, the building techniques and the nature of the bedrock. In order to point out the importance of capillary rising of water in the degradation of walls built of rammed earth, we took the example of Sidi Baba rampart. The analysis of the degradation of Sidi Baba rampart shows that he mostly suffered from a disorder related to a wet pathology. Thus, the solutions circulations, highlighted by the test water levels and changes in petrophysical parameters and the mobility of chemical elements along this profile are responsible for the phenomena of dissolution and crystallization. Alteration and loss of construction material, on the first meters from the ground, are attributed to capillary rising.
Author Keywords: Medina, Meknes, cultural heritages, rammed-earth, characterization, degradation, capillarity.
Volume 14, Issue 3, February 2016, Pages 645–652
Rabha Ajakane1
1 Département de Géologie, Université Moulay Ismaïl, Meknès, Maroc
Original language: French
Copyright © 2016 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The city of Meknes is rich of various cultural heritages built between the XVIth and the XIXth centuries and notably it's most important ramparts (more than 40 km length). It was protected in 1995 by UNESCO as World Heritage. These earthen walls are between 1.20 to 3 m wide and 7 to 12 m high. The ramparts have been constructed in rammed earth according to a traditional Moroccan method. A detailed observation of the ramparts of the city revealed that they suffer from many different damages and they are in very bad state, some of them are disappeared. We noted that they show some alterations like fissures and more important detachment. The study of the origins of the alterations shows that they mainly depend on the environment, like the water impact, the building techniques and the nature of the bedrock. In order to point out the importance of capillary rising of water in the degradation of walls built of rammed earth, we took the example of Sidi Baba rampart. The analysis of the degradation of Sidi Baba rampart shows that he mostly suffered from a disorder related to a wet pathology. Thus, the solutions circulations, highlighted by the test water levels and changes in petrophysical parameters and the mobility of chemical elements along this profile are responsible for the phenomena of dissolution and crystallization. Alteration and loss of construction material, on the first meters from the ground, are attributed to capillary rising.
Author Keywords: Medina, Meknes, cultural heritages, rammed-earth, characterization, degradation, capillarity.
Abstract: (french)
Riche de ses ressources naturelles et par sa situation géographique au centre du pays, Meknès l'est autant par son histoire. Grâce à son précieux héritage architectural, cette cité impériale dont les origines remontent au IXème siècle a été classée par l'UNESCO en 1996 comme patrimoine mondial de l'humanité. Parmi ces édifices se trouvent des remparts imposants qui clôturent la Médina sur plus de 40 Km de long. Ces édifices construits en pisé mesurent entre 1.20 à 3 m de large sur 7 à 12 m de hauteur. La plupart de ces remparts montrent des désordres caractéristique d'une pathologie humide dont les actions se traduisent par une évolution qui modifie la surface visible du monument (changement de patine, efflorescences, desquamations, désagrégations sableuses, fracturations, effondrement) dont les répercutions peuvent les menacer de ruine. L'étude menée sur le rempart de Sidi Baba a permis de montrer que les circulations de solutions, mises en évidence par le test des teneurs en eaux, par les fluctuations des paramètres pétrophysiques et par la mobilité des éléments chimiques sont responsables des phénomènes de dissolutions et de cristallisations. L'altération et la perte du matériel de construction, sur les premiers mètres depuis le sol, sont liées à des phénomènes de remontées des eaux par capillarité. L'action des remontées capillaires conduit à des transformations : (1) dans l'aspect générale des remparts exprimé par l'apparition de plusieurs formes de dégradations, les menaçant de disparition, (2) dans la structure concrétisée par le développement de macro-fissures et de macro-pores, et (3) dans la composition matérialisée par l'apparition de nouvelle phases minérales (dissolution / recristallisation).
Author Keywords: Médina, Meknès, patrimoine, pisé, caractérisation, dégradation, capillarité.
How to Cite this Article
Rabha Ajakane, “The capillary rise and degradation of Sidi Baba rampart (Medina of Meknes),” International Journal of Innovation and Applied Studies, vol. 14, no. 3, pp. 645–652, February 2016.
