https://doi.org/10.1051/epjconf/202532301004
A digital measurement approach for structural condition assessment of sewers
1 LNEC – National Laboratory for Civil Engineering, Scientific Instrumentation and Information Technologies Centre, Avenida do Brasil 101 1700-066 Lisbon, Portugal
2 LNEC – National Laboratory for Civil Engineering, Hydraulics and Environment Department, Avenida do Brasil 101 1700-066 Lisbon, Portugal
* Corresponding author: lfmartins@lnec.pt
Published online: 7 April 2025
This paper describes the application of photogrammetric digital reconstruction within the context of structural condition assessment of sewers. The acquisition of multiple images of the observation scenario and application of the bundle adjustment technique, supported by computational algorithms dedicated to image parallel computation and clustering, is the base for the approach adopted. An orthographic camera model with uniform scaling was adopted, supported by scale coefficients determined by the relation between digital and actual (SI traceable) dimensions of reference objects visible in the generated model. The paper details experimental and computational methodologies and presents several examples of digital sewer models. Finally, an evaluation of measurement data retrieved from the models is also shown, including identifying uncertainty components related to the input quantities and their propagation by the GUM method to the output quantity, considering the mathematical models related to the adopted camera model.
© The Authors, published by EDP Sciences, 2025
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
