2010 to assist Moroccan specialists in the evaluation of the damage and the emergency measures to undertake to prevent further risks and to identify the priorities to be considered for the development of a restoration project.
The mosque backs onto the ancient rampart, dating back to the Almoravids, and is harmoniously integrated into the centre of a dense urban district, grouping houses, shops, artisans as well as some public buildings. Somewhat sober in its exterior and interior decoration, the mosque comprises important architectural qualities and proportions. Its minaret, attaining 37 m in height, played a particularly remarkable townscape role, as an urban landmark in the general silhouette of the medina.
The collapsed building, visited on 19 April just two months after the catastrophe, had been left undisturbed except for the removal of rubble limited to the immediate need to extract the victims. Consequently, this state appeared as particularly significant in the appreciation of the extent of the accident and in making an initial diagnostic appraisal of elements likely to have been affected and also the objective causes of the collapse.
The analysis of work, visible earlier, or uncovered following the collapse, reveal in particular certain heterogeneity of the constitutive masonry structures of the buildings. Earlier photographs taken prior to the accident show the presence, on the western angle of the minaret, of a vertical open scission of about 10 m in length, particularly revealing of this original heterogeneity at the level of the foundations of the construction. The interior structure of the minaret also appears to have very particular characteristics which it would seem, differ from the usual construction styles used for most of the other similar buildings. The origin of the collapse could be attributed to a combination of different factors such as insufficient dimensions for the foundations, instability of the ground, probable gradual degradation of the land through lack of drainage and/or possible leaks in urban water pipes of the surrounding area of the building, and finally, sudden infiltration of this ground due to very heavy rainfall a
few days prior to the accident. A few days after the catastrophe
, H.M. King Mohamed VI issued instructions to the
Government to proceed as soon as possible with the reconstruction of the mosque, whilst respecting its original architecture. This principle of identical reconstruction is considered as acceptable insofar as the different criteria of historic value of the monument, the permanence of the function for which it had been built, the quality of image and integration into its urban environment are maintained. Nevertheless, this principle is only valid if, avoiding the pitfalls of a reconstruction "de style" more or less well interpreted; it is based on documentary and archaeological rigour, a genuine approach of identical reconstruction that must totally respect the authenticity of the form, material, and ancient substance of the parts of the building affected by the accident. However, the initial « defects » in the construction, decisive in triggering-off the collapse, should not be perpetuated or reproduced in the conception and implementation of the future project.
Hence, there is an immediate need for the implementation of the following main measures:
Removal and examination of the rubble, sort through the material and carry out shoring up activities;
Documentation: detailed recordings, collection and analysis of archives;
Investigations: careful dismantling, clearing of foundations with archaeological assistance, geotechnical soundings, search for possible drainage networks, recordings of outside ground cover;
Project: overall justification for the reconstruction, including principles to be followed with respect to authenticity;
Technical details of proposed intervention principles according to the different types of work, definition and technical implementation of work and materials, possible interior functional development annex to the work, outside development of the
State of conservation of World Heritage properties inscribed on the World Heritage List
WHC-10/34.COM/7B.Add, p. 110