Crack development monitoring using distributed fiber optic sensing technology

Cracking in clay is an important phenomenon that affects the long-term durability of many civil structures such as dams, levees, embankments, and landfills. In order to understand the behavior of cracking in clay, researchers at SRG, Hayato Nonaka and Yaobin Yang, conducted a four-point bending experiment on compacted kaolin clay beams. Distributed fiber optic sensors (DFOS) were embedded in the clay specimens at different heights and used for strain monitoring during crack development during beam bending. The applicability of DFOS for deformation monitoring and early warning of crack detection was investigated. A series of experiments are performed under different clay conditions by varying water content and compaction energy in order to understand the effect on the characteristics of crack initiation and propagation.

Compacted clay beam preparation and fiber optic sensor installation

Four-point bending test set-up