Simplified Nonlinear Static Procedures for Seismic Assessment of Masonry Infilled RC Structures

Existing Reinforced Concrete (RC) structures built in earthquake-prone regions during the ‘60s and ’70s of the past century generally result vulnerable to seismic actions. In such structures masonry walls are widely adopted both as internal partitions and external infills. Recent studies demonstrate that such components can significantly affect the global response of RC structures. Nevertheless, the mechanical contribution of infills is neglected in the common design practice and they are included in structural models by means of their weight and mass only. Both accurate modelling of masonry infill and practice-oriented approaches are nowadays available for simulating the nonlinear response of masonry walls, whereas no wellestablished methods exist for evaluating the global response of RC infilled frames by means of simplified Nonlinear Static (NLS) analysis. However, simplified procedures, based on extending the N2 Method, have been recently developed. Two of those procedures are summarised and compared in the present paper. More specifically, a parametric analysis is proposed with the aim to highlight their weaknesses and strengths. To do so, the results of both static and dynamic analyses are reported and discussed.