Nonlinear numerical parametric study of dowels for the seismic strengthening of RC frames with RC infill walls

Abstract

The parametric study of the contribution of dowels that connect a new reinforced concrete (RC) infill wall to the surrounding RC frame members was performed through nonlinear dynamic analyses of a numerical finite element (FE) model. The FE model was simulated in DIANA finite element analysis (FEA) software in order to study the effectiveness of the seismic retrofitting of existing structures with the conversion of selected bays into new infilled RC walls for the retrofitting of a multi-storey multi-bay RC frame building. A 2D frame was modelled and nonlinear transient analyses were performed in order to simulate the experimental results obtained from a full-scale experiment. The calibration of the FE model that simulated the experimental nonlinear cyclic behavior of the tested RC building is provided in [1]. Based on the calibration results it was concluded that the number of dowels used in the experiment resulted in a monolithic behavior of the RC infilled frame. In order to complement the experimental results and to study the interaction between RC infills and the bounding frame both in the global and local level, numerical simulation experiments were performed by reducing the number of dowels starting from a spacing of 100mm (monolithic) to a spacing of 380mm. Time-history was performed for each case and the results show that the maximum spacing of 380mm is sufficient to provide the required stiffness and ductility. In this paper, the FE model of the test specimen is described and presented along with a parametric study of the number of dowels connecting the wall to the bounding frame. These results contribute to the development of a general model for the application and the design of RC infills in existing RC frames.