Structural displacement sensing techniques for civil infrastructure: A review

A B S T R A C T It is important to assess, monitor, and control civil infrastructure displacements, and extensive work has been done to develop structural displacement sensing techniques. This paper presents a comprehensive review of structural displacement sensing techniques, with particular focus on those for civil infrastructures. The working principles of structural displacement sensing techniques using thirteen different sensors are fi rst reviewed, and the advantages and disadvantages of each sensor are brie fl y discussed. The disadvantages of single-mode sensor-based structural displacement estimation have been partially addressed by the use of multi-mode sensors. Thus, the studies on multi-mode sensor-based structural displacement estimation are reviewed. After that, fi eld applications of these techniques to building structures, bridge structures, and other structures are brie fl y reviewed. The remaining challenges for the real application of these techniques are summarized, and future research directions are provided.