Damage Location and Identification of Underground Structures Based on Brillouin Scattering and Extended Kalman Filter Technique

With the accumulation of damage to the structure in the long-term service state, the performance of materials, components, and structures will degrade to a certain extent. When encountering sudden situations such as a rainstorm, explosion, and earthquake, there may be damage endangering the safety of the whole underground structure, resulting in irreparable accidents. Due to the variety and complexity of urban underground structures, the traditional embedded optical fiber monitoring method is no longer applicable to a large number of existing urban underground pipe network structures. A novel method of damage location and identification based on Brillouin scattering and extended Kalman filter is proposed. The damage location is located by the Brillouin scattering principle through the multi-parameter fiber optic strain vibration cable. Then the dynamic parameters obtained from monitoring are used as the input characteristic parameters of the EKF method to identify the damage degree of the structure. Underground structures with different damage degrees are monitored through the finite element method and programming simulation. The results show that this method can quickly and accurately identify and locate the damage of underground structures, which are of great engineering significance.