Seismic performance of a full‐scale five‐story masonry‐infilled RC building subjected to substructured pseudodynamic tests

This paper discusses the results of a series of hybrid earthquake tests on a full-scale reinforced concrete (RC) building with masonry infills. The prototype was a five-story structure representing the vulnerable part of a typical RC building in Southern Europe, with beams stronger than the columns and masonry infill walls weaker than the surrounding frame elements. The specimen was subjected to a sequence of unidirectional earthquake simulations of increasing intensity up to conditions of significant damage to the infills, using the pseudodynamic (PsD) testing method with substructuring. The input ground motion was a real earthquake recording, slightly modified in amplitude and frequency to match the elastic design code spectrum. The physical substructure of the hybrid model consisted of the first story of a two-story mock-up structure built in the European Laboratory for Structural Assessment (ELSA); the second story ensured realistic boundary conditions at the top of the first one. The characteristics of stories two to five were simulated by a numerical finite-element model developed in OpenSEES and updated throughout the test sequence using data obtained from preceding tests. The experiments were terminated with the onset of a soft-story mechanism at the first story of the physical substructure for an earthquake with a peak ground acceleration of 0.3 g. The paper summarizes the key characteristics of the specimen and the major observations from the hybrid tests, illustrating the evolution of structural/nonstructural damage and the cyclic hysteretic building response. The attainment of significant damage limit states is correlated with experimentally defined engineering demand parameters and ground-motion intensity measures for the performance-based seismic assessment of buildings. Data and observations from these experiments add substantially to our understanding of the effects of masonry infills on the seismic behavior of RC-framed structures.