Conservation-oriented integrated approach for structural stability assessment of complex historic masonry structures

The paper presents a multidisciplinary approach for diagnosing the structural stability of the Takiyya of Ibrahim al-Gulshani in Historic Cairo using geometric and architectural documentation, field survey, laboratory tests, and numerical analyses under static and seismic conditions. The Takiyya, built during the Mamluk period, is an important medieval architectural complex in Egypt and has undergone multiple renovations. The field-testing includes geotechnical and geophysical investigations to evaluate the properties of the bearing soil beneath the monument. A 3D survey using Terrestrial Laser Scanning was employed to record Takiyya’s geometry. Terrestrial photogrammetry and high-resolution images accompanied by an in-situ damage survey were used to document cracking levels, stone weathering, and identification of decay patterns. Laboratory tests were conducted to assess the mineral composition, physical and mechanical properties of the construction materials to enable structural assessments. Data appraisal and integration into architectural drawings was used for mapping degradation patterns and the preservation state of the building. The documentation procedures combined with experiments were then employed to develop a model for structural analysis. Three-dimensional finite element numerical simulations employing macro-modelling approaches were performed for the Takiyya structures under various loading conditions, including modelling the bearing soil, resulting in good agreement with in-situ recorded structure damage patterns. The static and seismic nonlinear analyses helped identify the causes and effects of the current structural deficiencies. The adopted methodologies provided large amounts of information, permitting an improved understanding of existing damage and the assessment of the preservation state of the masonry structure. This project exists thanks to the Egyptian Ministry of Tourism and Antiquities (MoTA) and is funded by World Monument Fund (WMF) through various donors.