Numerical simulation of RC frames infilled with RC walls for seismic strengthening of existing structures

Although it is evident that the RC infill wall is an economic and practical way to improve the lateral strength of framed structures and a retrofitting method for existing buildings to withstand earthquake loads, there are still a lot of limitations regarding their application. Codes do not provide any guidance for their design and detailing or specific regulations for their interaction with the bounding frame. Furthermore, specific directions do not exist for the modelling or evaluation of frame bays converted into RC walls, depending on the type and details of the connection. A representation of the real behaviour of the wall and its interaction with the bounding frame during an earthquake is necessary to provide more accurate guiding information. For this aim, numerical models of this structural system were developed and are presented in this paper. The experimental results of the project SERFIN, which was a full-scale four-storey model tested with the pseudo-dynamic method at the ELSA facility of the Joint Research Centre in Ispra, were used to calibrate the numerical models. Two-dimensional (2D) frames were modelled in DIANA FEA, and nonlinear transient analyses were performed to simulate the experimental results obtained from the SERFIN full-scale experiment. In this paper, the FE model simulation of the test specimen is presented along with a comparison between the experimental results and the numerical ones. It was concluded that the developed numerical models capture effectively the behaviour of the studied structural system and can be used for parametric studies to examine the effects of the number of dowels on the behaviour of the system and propose design guidelines based on the results of the parametric study.