Seismic response of reinforced concrete coupled walls

This dissertation presents an analysis of the response mechanism of RC walls coupled by slabs without coupling beams. Special attention was devoted to the variable interaction between the slabs and walls and its role in overall seismic behaviour. Adequate numerical models are essential for accurately capturing the interaction between slabs and walls. This dissertation employs the MVLEM numerical model, developed at UL FGG, to describe the response of walls. The MVLEM model was complemented by existing numerical models of RC beams, columns, and beam–column joints. The capabilities of these models were validated by simulating the response of a U-shaped core wall tested at UCLouvain and by two full-scale 10-storey RC buildings tested on the world’s largest shaking table in the E-Defense centre in Japan. The basic response mechanism of RC walls and important parameters influencing this response, particularly the roles of the flexural stiffness and capacity of coupling slabs, were investigated through analysis of the experiments conducted within the HORIZON 2020 SERA-TA project ‘Influence of floorto-wall interaction on the seismic response of coupled wall systems’. Shaking table tests were not conducted as part of the work for this dissertation. However, a numerical simulation of the observed response and an extensive sensitivity study were performed. Previously validated numerical models were used. The test was simulated successfully. The sensitivity study produced valuable information about the influence of the interaction between the slabs and walls and its role in the overall seismic behaviour of RC walls coupled with slabs. To generalise the observations of the shaking table experiment and post-experimental study, an extensive parametric study was conducted on buildings with different configurations (e.g. varying slabto-wall strength ratios, different wall aspect ratios, and subjected to different sets of accelerograms, etc.). The results of the parametric study confirmed the experimental findings. It was shown that for specific wall configurations, the coupling provided only by slabs is not negligible. In cases in which interaction between the slabs and walls is important, the response of the walls is different from that predicted in the design. A study on the inelastic shear force amplification in RC walls coupled only by slabs was conducted. Simple equations for reliable estimation of the demand were proposed. The proposed equations were validated across all buildings considered in the parametric study. Relatively accurate estimates of the shear forces were obtained. Finally, based on the knowledge gained, a simple and efficient pushover-based method for the seismic design of RC walls coupled only by slabs was proposed. The responses of structures designed according to the proposed method were improved in comparison to those obtained for traditionally designed structures.