Enhancing the seismic resilience of the Batıayaz masonry bridge, aftermath of 2023 Kahramanmaraş earthquakes, using iron and FRP clamp-dowel connectors in the arch: Failure tests and numerical modelling

Abstract

Historic bridges are invaluable cultural landmarks that embody the architectural and engineering achievements of past civilizations. Preserving these structures, which are often vulnerable to seismic activity, is essential to safeguarding cultural heritage for future generations. This study examines the Batıayaz Bridge, which sustained significant damage in the February 8, 2023, Kahramanmaraş earthquakes. Originally, iron connectors were used between stones in the arch section of the bridge. This research investigates the potential of using FRP (Fiber Reinforced Polymer) connectors as an alternative to iron for enhancing the seismic resilience of the arch. The bridge was reinforced with both FRP-metal clamps and dowel connectors, enabling a comparison of its seismic performance under each configuration. The connectors were carefully installed between stones with specialized adhesives and Khorasan mortar. Reinforced stone elements then underwent compressive and tensile testing, yielding essential data on the connectors’ normal and shear stiffness, as well as the mechanical properties of the Khorasan mortar. A three-dimensional model of the bridge was created in FLAC3D software using the finite difference method. Individual stone elements were modeled with brick and wedge components, incorporating experimentally derived stiffness values. The Mohr-Coulomb material model was applied to both the stone elements and the foundation soil, with non-reflecting boundary conditions set at the model’s edges. Ten different ground motion simulations were conducted to assess seismic behavior. The seismic analyses for the two models, with FRP and metal connectors in the arch, indicated that both types significantly improved the bridge’s seismic resistance. Results revealed that the use of FRP and iron mechanical connectors in the arch section substantially modified the bridge’s seismic response compared to the configuration without connectors. Besides, no major differences were observed between FRP and iron connectors in terms of enhancing seismic resilience of the bridge. The findings suggest that corrosion-resistant FRP connectors provide a durable alternative to metal connectors, which are prone to degradation over time. Thus, FRP connectors represent a promising option for the long-term seismic strengthening and restoration of historic bridges.