Spatiotemporal settlement deformation characteristics analysis of rockfill dam with anti-impact FBG sensing array

With the widespread application of rockfill dams, preventing potential failures in rockfill dams during the construction and operation periods is critically important. Settlement monitoring of rockfill dams is an efficient and feasible method of the disaster prevention. However, the current dam settlement monitoring technology is mostly point-based and has a low survival rate with the rockfill construction condition. To address the issue, the FBG sensing array is proposed to continuously obtain the rockfill dam settlement in space and time. The FBG sensing array employs advanced grating direct writing technology and packaging method, which has the advantages of high sensitivity and impact resistance. Furthermore, tests were conducted to validate the sensor performance. Finally, the proposed method was applied to the settlement monitoring of a rockfill dam on the Jinsha River in Sichuan, China. The research results demonstrate that the installed FBG sensing array successfully captures spatiotemporal continuous settlement data of the rockfill dam. Analysis of on-site monitoring data revealed the spatiotemporal deformation characteristics of the rockfill dam. Intensive rainfall significantly contributed to settlement in the middle and upper parts of the rockfill dam during operation. The proposed method comprehensively captures dam deformation data in advance, which is of great significance for the early warning of dam instability.