Determining the possibility of high-precision deformation measurement in building structures using fiber-optic methods

The object of this study is the deformation process in reinforced-concrete structural elements equipped with embedded fiber-optic sensors. The problem addressed corresponds to unresolved issues identified in previous studies – namely, the lack of standardized quantitative evaluation of accuracy and stability in fiber-optic deformation measurement. Despite high laboratory precision, existing methods show reduced long-term reliability, temperature-strain cross-sensitivity, and calibration inconsistency when applied to real structures. The main results show that fiber Bragg grating (FBG) and interferometric sensors achieved sub-micrometer deformation resolution with deviations below 2–3 με and long-term drift under 0.5%. Measurements remained stable under variable loading and temperature, confirming high reproducibility and electromagnetic immunity. These findings validate the hypothesis that optical wavelength shifts directly correspond to mechanical strain, ensuring reliable strain detection without recalibration. This effectiveness stems from the intrinsic photoelastic coupling and refractive-index sensitivity of the optical fiber, which provide nanometric resolution, corrosion resistance, and long-term operational stability. The proposed method is applicable for long-term monitoring of bridges, tunnels, and high-rise facilities exposed to environmental and cyclic stresses. Therefore, research on high-precision fiber-optic deformation measurement remains scientifically relevant for improving the safety and durability of modern civil engineering structures.