Seismic performance of masonry infilled RC frames provided in the appendix of IS 2800

Document Type : Original Article

Authors

1 M.Sc., Department of Civil Engineering, Faculty of Civil Engineering and Architecture, Malayer University, Malayer, Iran

2 Associate Prof., Department of Civil Engineering, Faculty of Civil Engineering and Architecture, Malayer University, Malayer, Iran

10.22065/jsce.2024.407860.3172

Abstract

Most researches on masonry infill walls have shown that the presence of such walls in framed structures increases their stiffness and resistance. However, the presence of panels is not always beneficial and may lead to a brittle failure in some cases. To quantitatively investigate this issue, it is necessary to consider the infill wall as a structural member and explicitly model it in framed structures. Recently, the Building Design Code against Earthquake (IS 2800) has provided an approach for the explicit analysis and design of infilled frames in its sixth appendix using an equivalent strut model. In this solution, by reducing the response modification factor of the structural frame with infill walls to 3 and modeling the infill walls using the equivalent strut method and redistributing the forces in the equivalent truss system, the structural adequacy of the beams, columns, and infill walls in the entire frame is checked. In the present study, five reinforced concrete moment frames, including one bare frame (with intermediate ductility) and four infilled frames with different infill wall arrangements according to the sixth appendix of IS 2800, are analyzed and designed, and subsequently, the seismic performance of their members is investigated using the nonlinear static analysis method (the coefficient method). The results show that although the addition of masonry panels to the structures increases their stiffness and resistance and improves the performance of the beams, however, the lower columns exceed the life safety performance level and sometimes reach the collapse prevention level. Therefore, considering a response modification factor of 3 for all infilled frames with different infill wall arrangements on the floors does not seem to be accurate.

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Articles in Press, Accepted Manuscript
Available Online from 14 March 2024
  • Receive Date: 22 August 2023
  • Revise Date: 26 January 2024
  • Accept Date: 14 March 2024