Underground construction activities, such as tunnelling, cause local ground movements to occur. Nearby surface structures interact with the moving ground, potentially leading to building damage. Although it is understood that the severity of building damage is influenced by the façade opening ratio (OpR) and the stiffness of the floors, experimental work in this area is lacking. This paper describes the specification and design of an experimental campaign on brick masonry buildings subjected to vertical base movements. The specimens are half-scale models of walls of two-storey buildings; models with different window arrangements and with/without floor slabs are examined. To design the experimental setup, 3D finite element analyses of the model walls were conducted. Key analysis results, presented in this paper, indicate how the examined structural properties (OpR, building weight, floor stiffness) are expected to influence the patterns of damage in the masonry. The finite element results are also used to design an instrumentation system comprising Fibre Bragg Grating (FBG) sensors and a digital image correlation (DIC) system. Data from the tests will support the formulation and validation of structural models for predicting tunnelling-induced damage in masonry buildings.

@en

The current article presents a case study of the settlement response of the historic Hoca Pasha Mosque that involves uncertainties arising from the complex excavation activities, soil properties, building materials, and geometry and the presence of pre-existing cracks in the mosque’s walls. The objective is to demonstrate the added value of a two-stage numerical analysis approach for the assessment of the settlement response of the building. The first stage comprises analyses of the structural behavior using the monitored settlements for each wall. The second stage examines the behavior of the complete building as a whole. The effects of soil-structure interaction and the pre-existing cracks are considered through discrete interface elements. It is shown that executed simulations can reasonably reproduce the overall settlement response, resulting stresses and the pre-existing crack activities. The parametric analyses in the second stage also produce generalizable results, of use beyond the specific case. Namely, as the soil/structure stiffness ratio increases the settlement-induced vulnerability increases. Including soil-structure interaction in the analyses reduces tensile strains due to differential settlements. Including pre-existing cracks reduces tensile strains in the vicinity of the cracks but results in an increase of stresses in neighboring sections.

@en

In this paper, limiting tensile strain method (LTSM) is reviewed, and advantages and disadvantages resulted from the simplicity of this method are examined in the light of the findings of the existing experimental and numerical studies. Using the viewpoint of the transfer functions for the LTSM, a more independent sight for the interpretation of the relationships between deflection ratio, structure’s geometry, longitudinal/shear stiffness ratio and the limiting tensile strain is provided. In addition, the effect of average horizontal strain is included simply in the modified deep beam equations. Using reported data and observed damage classes of real and simulated case studies available in the literature, back-calculations for the coefficients of the transfer function are made. After comparing the back-calculated coefficients to the original coefficients of the LTSM, it is shown that observed damage and measured crack widths are reasonably compatible with the proposed limiting tensile strain boundaries. Also, it is shown that for the cases in which moderate or higher damage was observed, the original deep beam equations tend to underestimate the resultant damage.@en

This paper presents a finite element simulation of the response of the historic Hoca Pasha Mosque in Istanbul to ground settlements stemming from a neighboring shaft excavation. The focus is on the behavior of major existing cracks. A linear elastic material model is adopted for the masonry walls. The settlement analyses are performed considering possible free–field ground settlement profiles. The openings and closings of the existing cracks are tracked by means of interface elements. The results show that settlement response of the mosque was more sensitive to the curvature of the chosen settlement profile rather than to the mechanical properties of the structure. Furthermore, for the considered settlement scenarios, the effect of the existing cracks is negligible on the overall response.@en