Cracks are the most common lesion in water-wading structures such as dams and sluices, which have an important impact on the durability of concrete materials and the safety of structures. The emergence of cracks is also regarded as a precursor to the destruction of buildings. However, the randomness and concealment of cracks are strong, which bring great difficulty to real-time and accurate capture. This paper focuses on Pulse Pre-Pump Brillouin Optical Time Domain Analysis (PPP-BOTDA) and studies the principle and realization method of PPPBOTDA optical fiber sensing for concrete structure strain. On this basis, several groups of monitoring experiment for crack initiation location and propagation process of concrete structures are carried out. In the paper, the relationship between force-light-opening is studied and the influence of angle between optical fiber and crack on monitoring results is analyzed. Finally, a monitoring model for concrete cracks based on optical fiber strain sensing is constructed.
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