Movement detection in tunneling applications using new deformed point registration

Timely detection of ground movement is critical in geotechnical engineering to prevent failures that could result in loss of life or property damage. In tunneling applications, this task is commonly referred to as convergence monitoring, which has conventionally relied on geodetic instruments such as total stations, or, more recently, on advanced technologies such as mobile laser scanning. A new computer vision-based approach, requiring only a small number of targets, offers a faster and more cost-effective alternative for ground deformation monitoring. The method introduces interconnecting distance embedding (IDE), which captures changes in pairwise distances between markers before and after deformation. The pairwise distances serve as an embedding of the spatial configuration of the markers; however, a point registration algorithm is required to compare movement across different time steps. Compared with conventional registration techniques—such as mean squared error or least absolute deviations, which perform well for a rigid body but lose effectiveness when deformation alters point configurations—a new IDE-based algorithm was developed that enables more robust tracking. In addition, computer vision offers richer insights at lower cost, supporting both quasi-static and short-interval monitoring (e.g., hourly or daily). Furthermore, in the New Australian Tunneling Method, it further streamlines the integration of convergence monitoring into design workflows, thereby enhancing efficiency, flexibility, and reliability.