Abstract
Introduction. The increasing demand for green and intelligent civil infrastructures necessitates high-precision Internet of Things (IoT) monitoring systems. Given the high sensitivity of geotechnical engineering to soil strains, it is essential to develop precise measurement approaches that can accurately capture soil strains ranging from micro-strain to large strains. In recent years, advancements in fibre optic sensing technology have enabled accurate measurements within geotechnical engineering. However, there is still a need to enhance measurement approaches for fibre optic sensing technologies across various strain levels. This study investigates several fibre optic sensing technologies, including point-distributed, array sensing, and distributed fibre optic sensors, and provides a comprehensive review of recent advancements in fibre optic sensing for the field of geotechnical engineering. Materials and methods. Innovative methods and devices for high-precision small-strain fibre optic sensing are detailed. Additionally, a novel integrated fibre optic sensor device capable of measuring water pressure and total soil pressure using a signal transducer is introduced. Results. The study also explores the use of 3D printing technology in fabricating these transducers. A fibre optic sensing method for monitoring cracks is presented, encompassing physical fabrication, calibration tests, and field engineering application verification. Conclusions. The fibre optic sensing methods proposed in this study offer effective solutions for accurate measurement in geotechnical engineering across different environmental and disaster conditions.