Network analysis of Masonry: Indicator Computations for Detecting Soil Defect Impact

Masonry structures definitely suffer their intrinsically poor tensile strength capacities. As a consequence, thinking about an efficient manner to prevent or reduce the impact of soil defects on un-reinforced masonry buildings remains an important challenge for most of the engineers: it is obvious that some smart modifications introduced during the conception or design steps would be likely to strongly improve the future behaviour of the structural system. After a short introduction to related challenges, the paper discusses the interest to dispose of a calculation tool likely to detect and objectively quantify the impact of a given soil defect on a given building. Then, the recourse to a control-profile method is proposed: it allows to associate an objective value with a configuration composed of a given building morphology submitted to a given set of loads and perturbed by a given soil defect. The first step consists in a quick calculation of the building using a simplified FE approach (with and without the soil defect). The second step relies on an arbitrary distributed network allowing scanning the general stress states obtained by the end of the first step: inside each control-profile of the network, an equivalent force pattern is become computed that would later be used for calculating a conventional fictive reinforcement pattern associated to the concerned influence zone. The succession of fictive reinforcement patterns gives birth to both the succession of codes (DNA-codes) corresponding to the configuration with and without the soil defects. In the third step, the comparison of these code successions allows estimating if an impact of the soil defect is detected on the building and, once the case occurs, quantifying this impact through a global indicator computed on the basis of each zonal contribution to the fictive reinforcement. Finally, the paper illustrates the process on the case of the former Choiseul Seminary, an ancient un-reinforced masonry building located in a karstic region of southern Belgium.