Optical-Fiber-Embedded Beam for Subgrade Distributed Settlement Monitoring: Experiments and Numerical Modeling

In this study, Brillouin optical time domain analysis (BOTDA) sensing technology was utilized for monitoring settlement in a similarity model of highway subgrade. As contact winding cannot be used an fiber that is buried directly the soil, uncoupling between and soil can occur. Thus, optical-fiber-embedded beam (OFEB) developed, method measuring calculating beam’s deformation proposed. A calibration test on subgrade were carried out to investigate applicability accuracy OFEB. It concluded OFEB accurately measure deflection, maximum relative error measurements by displacement transducer approximately 5%. The embedded into monitor settlement. deflection found close over certain range, with below 8.1%. large-range distributed numerical simulation performed identify appropriate dimensions material design parameters, thereby extending measurement range before decoupling occurs. enhancement based preliminary experiments study enables further investigation monitoring.