What the study found
Full-length injected tie-rods (steel rods injected into masonry to strengthen it) improved the out-of-plane seismic behavior of unreinforced masonry walls. The study found that they did not substantially increase initial stiffness, but they did improve out-of-plane capacity, post-peak stiffness, and drift control.
Why the authors say this matters
The authors present full-length injected tie-rods as a feasible strengthening method with minimal visual impact for heritage masonry structures. The study suggests that the approach can support practical design of retrofitted walls through both numerical modeling and an analytical method.
What the researchers tested
The researchers studied U-shaped unreinforced masonry walls retrofitted with full-length injected tie-rods using validated finite element (FE) modeling, parametric analyses, dynamic simulations, and a design-oriented kinematic approach. They compared FE models against literature experimental data and examined both solid-element and truss-element modeling strategies.
What worked and what didn't
The FE models reproduced wall response and the bond mechanism of injected rods well, and the truss-element model was about as accurate as the solid-element model while being simpler for large-scale analyses. Multiple tie-rods at two heights and larger rod diameters were most effective, although the benefit decreased beyond a certain diameter. Dynamic simulations showed improved drift control and delayed failure across different excitations.
What to keep in mind
The study focuses on U-shaped unreinforced masonry walls, so its results are specific to that configuration. The abstract does not describe experimental testing done directly in this study or provide broader limitations beyond the reported modeling scope.
Key points
- Full-length injected tie-rods improved out-of-plane capacity and post-peak stiffness in unreinforced masonry walls.
- Initial stiffness changed little after retrofitting.
- Two tie-rods at different heights and larger diameters were the most effective configuration, with diminishing gains beyond a threshold diameter.
- A truss-element FE model gave similar accuracy to a solid-element model and was simpler for large analyses.
- The modified kinematic analysis matched FE predictions with an average error of about 7%.
Disclosure
- Research title:
- Injected tie-rods improved out-of-plane masonry wall capacity
- Authors:
- Gokhan Yucel
- Institutions:
- Osmaniye Korkut Ata University
- Publication date:
- 2026-04-05
- OpenAlex record:
- View
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