The Church of the Nativity in Bethlehem: Non-destructive tests for the structural knowledge

This paper deals with the activities performed within an integrated knowledge plan finalized to the restoration design of the Church of the Nativity in Bethlehem, Palestine. A multipurpose and interdisciplinary research work was carried out, which is a representative example and benchmark for the methodological approach concerning conservation and restoration of monuments and historical sites. According to the work plan of the project, seven coordinate research teams worked on the same site in different or partially overlapping periods. Their activity concerned historical researches, laser scanning survey, non-destructive tests on masonry structures, inspections and tests on roof timber structures, identification of structural damage, analysis of plasters and mosaics. The mutual interchange of information and data, as well as the integrated and interrelated work allowed to achieving an accurate and reliable diagnosis of the construction, which was the basis for the restoration design. This paper describes some results of the in situ testing performed by the Benecon Group of the Second University of Naples (Italy), focused on the acquisition of all the data needed for evaluating the static safety of the whole Church. Sonic and ultrasonic pulse velocity testing, surface penetrating radar test, infrared thermography analysis, fiberscope inspection, laboratory tests on masonry cores and mortar specimens, temperature and moisture measures were performed as complementary methods. The paper describes the equipment and testing arrangement and the main results and outcomes that allowed to assessing the structure safety and drawing recommendations for the restoration of the Church and for the conservation management plan. (C) 2012 Elsevier Masson SAS. All rights reserved.