Terrestrial Laserscanning in Deformation Measurements of Structures

Terrestrial laserscanning broadens its application area in the civil engineering industry. This paper discusses the potential of the technology through the example of the deformation measurement of a new Hungarian bridge on the Danube during its load testing procedure. The paper discusses the complex procedure from the field measurement through primary data processing and the analysis of the laserscanned data. Comparison analysis between laserscanning and the traditional geodetic methods (such as high-precision leveling) is also described. For the accuracy analysis, laboratory deformation measurements have been carried out. During the controlled load testing of a full-scale steel portal frame each load phases were captured by terrestrial laserscanner. The displacements of dedicated points of the structure were measured by high-precision inductive transducers; thus the results of both methods can be directly compared. The paper is completed by a mathematical modeling of the error propagation of the measurement and the most relevant quality features are derived. By computing the accuracy measures of the terrestrial laserscanning the overall technology can be qualified and calibrated. Terrestrial laserscanning has proved its potential in such engineering projects. Data can be acquired about areas, not only about discrete points. In case of sizeable structures, such as bridges, information can be gathered about remote areas and points with limited accessibility.