Unreinforced Masonry (URM) has been extensively used as a construction material in mass structures with predominant compression load paths. Despite its reasonably established performance under gravity actions, it can be quite vulnerable to seismic loading, predominantly due to its limited tensile strength and associated quasi-brittle failure modes. Therefore, a reliable seismic assessment of URM structures, including heritage buildings, is vital to ensure life safety and minimise their risk of collapse. This can assist in implementing effective remedial measures, if required, to ensure desirable performance level in future events. Despite significant advancements in masonry research, practical assessment of URM has always been a challenge for structural engineers due to the complexity of the mechanics and geometry involved. Different modelling approaches have been trialled so far, which are typically based on equivalent frame, discrete and continuum elements in 2D/3D domains. In this paper, a simplified nonlinear model is introduced within the framework of conventional layered shell elements, which can be easily implemented in commonly used FE packages, e.g. ETABS and SAP2000. In this model, the URM shell element comprises three layers accounting for cohesion and axial-frictional behaviour parallel and perpendicular to the bed joints, where the mechanical properties can be adjusted for various masonry configurations. The performance of the proposed model is validated against several experimental tests available in the literature, where a good correlation with test data is achieved across various design scenarios and loading conditions.
Abstract
Unreinforced Masonry (URM) has been extensively used as a construction material in mass structures with predominant compression load paths. Despite its reasonably established performance under gravity actions, it can be quite vulnerable to seismic loading, predominantly due to [...]
Existing heritage buildings are often composed of diverse structural typologies, representing a challenge for structural analysis. This work investigates the use of nonlinear static analysis to assess the seismic behaviour of hybrid timber-masonry buildings. The proposed methodology includes the use of Lumped Plasticity Models (LPM) and Macro-Mechanical Finite Element (FE) approaches to simulate the response of structures composed of timber frames and masonry walls. Benchmark experiments on timber and masonry specimens subjected to lateral loads are used to calibrate the constitutive laws governing the behaviour of the proposed models. The calibrated models are used to appraise the seismic response of an existing timber-masonry building located in the historical centre of Valparaíso (Chile). The results predict the nonlinear acceleration-displacement capacity of the buildings, as well as the expected damage of the structure, revealing the potential local and global failure mechanisms.
Abstract
Existing heritage buildings are often composed of diverse structural typologies, representing a challenge for structural analysis. This work investigates the use of nonlinear static analysis to assess the seismic behaviour of hybrid timber-masonry buildings. [...]
A Simplified Modelling Approach for the Practical Engineering Assessment of Unreinforced Masonry Structures Using Layered Shell Elements 