Effect of Precompression and Material Uncertainty on the In-Plane Behavior of URM Pier–Spandrel Systems

Abstract

Theoretical and experimental studies on loadbearing masonry walls have shown the significant influence of the axial load level (i.e., precompression) and wall aspect ratio on in-plane lateral resistance. Nonetheless, the impact of the precompression and spatial variability of the material properties needs to be further investigated at the scale of walls with openings. This study presents a stochastic analysis of unreinforced (URM) pier–spandrel systems subjected to both axial loads on piers and lateral loads, considering the spatial variation in material properties. A discontinuum-based computational model was utilized to assess the force–displacement behavior of a benchmark pier–spandrel structure under different vertical precompression levels on piers. A total of 750 simulations were carried out to propagate material uncertainties in lateral load analysis. The proposed modeling strategy, based on the discrete element method, explicitly represents joint openings, sliding, and crushing phenomena at the contact points defined between the adjacent discrete rigid blocks. According to the validated computational modeling strategy, meaningful inferences were made regarding the effect of the precompression level on the maximum displacement and ultimate lateral load-carrying capacity of the benchmark URM pier–spandrel system. The results showed that vertical pressure on piers had considerable influence on the displacement ductility of the system while yielding less variation in the displacement capacity. Furthermore, the appealing feature of the spatial probabilistic analysis is noted in the variation in the lateral load-carrying capacity of the structural system.

Sensitivity Analysis of Dry-Joint Stone Masonry Walls Using Discrete Element Method

“…The formulation, initially developed by [10,11] for the study of jointed rocks, was in fact subsequently employed with success to study other discontinuous media, such as masonry. Studies over the suitability of DEM to replicate the experimental behaviour masonry can be found, amongst others, in [12,13,14], while [15] focused specifically on simulating the behaviour of dry joint masonry under in-plane and out-of-plane actions.…”

“…For a detailed description of the method, as well as the available modelling strategies which can be implemented in DEM to simulate masonry -which is beyond the scope of this paper -the reader is redirected, amongst others, to [10][11][12][13][14][15][16]. It is noted that, in DEM-based software packages such as 3DEC, masonry is usually modelled as either (a) an assembly of rigid blocks, with system deformability lumped into the nonlinear zero thickness interfaces, or (b) an assembly of linear elastic, isotropic deformable bodies and nonlinear interfaces, in which case system deformability needs to be carefully distributed onto both constituents.…”