A novel strengthening process for masonry tower-type structures with irregular geometry using carbon fiber composite ropes

Abstract

Following the February 6, 2023, earthquakes in Türkiye, visible damage reports were received from the historical Antalya Clock Tower. Initial field assessments revealed several structural cracks, and eight of these were selected for long-term monitoring. During this period, both free and forced vibration data were collected using triaxial accelerometers to better understand the tower’s dynamic characteristics. After approximately one month, the observed crack propagation indicated a rapid degradation of structural integrity, prompting the implementation of an emergency strengthening intervention. Temporary confinement elements were installed to stabilize the structure and prevent further deterioration. Subsequently, Ground Penetrating Radar (GPR) surveys and in-situ material tests were conducted to identify internal voids and evaluate the existing masonry properties. Using the data obtained, a detailed finite element model of the tower was created. This model was first calibrated using the recorded vibration data, and then subjected to a series of analyses to investigate seismic behavior. Response Spectrum and nonlinear Pushover analyses were performed to evaluate the tower’s performance and to guide the design of a permanent strengthening strategy. The selected solution involved externally wrapping the tower with carbon fiber composite ropes and filling cracks and voids with injection grout. The number, diameter, and layout of the ropes were optimized through parametric simulations and then implemented on-site. Post-strengthening monitoring confirmed the effectiveness of the intervention, as no further crack widening was detected. This study presents a complete assessment, analysis, and strengthening process for a historical masonry tower, emphasizing the critical role of staged diagnostics and advanced numerical modeling in heritage conservation.