A 3-d laser scanning system and scan data processing method for the monitoring of tunnel deformations

TL;DR: The mobile multi-sensor system Orthos Plus for the monitoring and mapping of tunnel walls, a scan data processing method for the evaluation of 3-d tunnel wall displacements from subsequent wall scans and, finally, a virtual reality tool supporting the interpretation of data are presented.

Abstract: The paper presents the mobile multi sensor system Orthos Plus for the monitoring and mapping of tunnel walls, a scan data processing method for the evaluation of 3-d tunnel wall displacements from subsequent wall scans and, finally, a Virtual Reality tool supporting the interpretation of data. The measuring system consists of a 3-d laserscanner, a motorized totalstation and a digital camera that are integrated on a light metal frame that is installed on a mobile platform. It has been designed to perform tunnel measurements most efficiently and to meet the special requirements of tunnels under construction. The evaluation of 3-d displacements is based on a 3-d matching algorithm that takes advantage from the particular conditions of tunnel (shotcrete) surfaces. The Virtual Reality tool allows for the viewing of data in a 3-d Virtual Reality tunnel model and of their animation in time and space in order to support their understanding in an optimal way. The measuring system Orthos Plus has been developed in the course of a national research project, the 3-d matching method in the frame of the Austrian Christian Doppler Laboratory Spatial Data from Laser Scanning and Remote Sensing and the VR tool in the Austrian COMET K1 Competence Center VRVis Center. * Corresponding author. This is useful to know for communication with the appropriate person in cases with more than one author.