Computers and Concrete

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Experimental and analytical study of squat walls with alternative detailing

  • Leonardo M. Massone (Department of Civil Engineering, University of Chile) ;
  • Cristhofer N. Letelier (Department of Civil Engineering, University of Chile) ;
  • Cristobal F. Soto (Department of Civil Engineering, University of Chile) ;
  • Felipe A. Yanez (Department of Civil Engineering, University of Chile) ;
  • Fabian R. Rojas (Department of Civil Engineering, University of Chile)
  • Received : 2023.11.29
  • Accepted : 2024.02.05
  • Published : 2024.05.25
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Abstract

In squat reinforced concrete walls, the displacement capacity for lateral deformation is low and the ability to resist the axial load can quickly be lost, generating collapse. This work consists of testing two squat reinforced concrete walls. One of the specimens is built with conventional detailing of reinforced concrete walls, while the second specimen is built applying an alternative design, including stirrups along the diagonal of the wall to improve its ductility. This solution differs from the detailing of beams or coupling elements that suggest building elements equivalent to columns located diagonally in the element. The dimensions of both specimens correspond to a wall with a low aspect ratio (1:1), where the height and length of the specimen are 1.4 m, with a thickness of 120 mm. The alternative wall included stirrups placed diagonally covering approximately 25% of the diagonal strut of the wall with alternative detailing. The walls were tested under a constant axial load of 0.1f'cAg and a cyclic lateral displacement was applied in the upper part of the wall. The results indicate that the lateral strength is almost identical between both specimens. On the other hand, the lateral displacement capacity increased by 25% with the alternative detailing, but it was also able to maintain the 3 complete hysteretic cycles up to a drift of 2.5%, reaching longitudinal reinforcement fracture, while the base specimen only reached the first cycle of 2% with rapid degradation due to failure of the diagonal compression strut. The alternative design also allows 46% more energy dissipation than the conventional design. A model was used to capture the global response, correctly representing the observed behavior. A parametric study with the model, varying the reinforcement amount and aspect ratio, was performed, indicating that the effectiveness of the alternative detailing can double de drift capacity for the case with a low aspect ratio (1.1) and a large longitudinal steel amount (1% in the web, 5% in the boundary), which decreases with lower amounts of longitudinal reinforcement and with the increment of aspect ratio, indicating that the alternative detailing approach is reasonable for walls with an aspect ratio up to 2, especially if the amount of longitudinal reinforcement is high.

Keywords

Acknowledgement

This research was financed by the National Agency for Research and Development (ANID) through the Fondecyt Regular 2020 N°1200023 project. Additionally, the authors express their gratitude to Mr. Pedro Soto for his valuable assistance with wall testing.

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