PSI - Issue 64

Stefano Belliazzi et al. / Procedia Structural Integrity 64 (2024) 612–620 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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4. Analyses results The structural analyses have been evaluated on a sample of over 32,000 buildings generated by the Monte Carlo analyses. Two different sets of structural models are defined depending on the number of storeys: building model with more than 1 storey. The structural models with more than 1 storey are modelled as building model with 1 storey where the upper storeys are modelled by increasing the normal load applied at the top of the masonry walls. The normal load is increased with a parameter defined between 10 and 30% of the ultimate load of the cross-section. In Fig. 3 and Fig. 4, the results of the structural analyses are shown by the means of histograms for masonry piers (AB and PQ) and spandrel (DL) of structural models for each flexural and shear local mechanisms failure. The masonry pier PQ exhibits a high vulnerability to the local mechanisms activation, especially to flexural failure mode, due to the settlements applied at the bottom of the pier and the consequentially induced tensile axial load in the masonry pier. In fact, tensile axial load in masonry pier has a strong impact on the flexural and shear capacity evaluation, as well known from Heyman's assumption: simple masonry is unable to carry any tensile axial load. Therefore, the axial load used in the flexural and shear capacity is evaluated as the difference between the compressive axial load due to gravitational loads (self-weight and floor loads) and the tensile axial load due to the settlement. Increasing the settlement, the masonry pier AB is constantly compressed in the performed static linear analyses. The masonry pier PQ is compressed or in tension depending on the difference between gravitational axial loads and the tensile axial load induced by the settlement. In structural model characterized by 1 storey (Fig. 3), the sliding shear failure mode distribution is similar in the piers AB and PQ while the flexural and diagonal shear failure mode are more easily reached in the PQ pier due to tensile axial load. ▪ ▪ building model with 1 storey;

Fig. 3. Analysis results for structural models with 1 storey.