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Comparison between 2D and 3D ERT inversion for engineering site investigations – a case study from Oslo Harbour
Author(s) -
Lysdahl Asgeir Kydland,
Bazin Sara,
Christensen Craig,
Ahrens Sven,
Günther Thomas,
Pfaffhuber Andreas A.
Publication year - 2017
Publication title -
near surface geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.639
H-Index - 39
eISSN - 1873-0604
pISSN - 1569-4445
DOI - 10.3997/1873-0604.2016052
Subject(s) - harbour , inversion (geology) , geology , excavation , engineering geology , regional geology , economic geology , environmental geology , electrical resistivity tomography , telmatology , seismology , hydrogeology , electrical resistivity and conductivity , geotechnical engineering , engineering , computer science , volcanism , tectonics , electrical engineering , programming language
Excavation and piling works related to seafront development in Oslo’s historic harbour area need to mitigate the risk of damaging buried archaeological objects. In the Bjørvika harbour in Oslo, Norway, electrical resistivity tomography was performed to detect structures with potential archaeological value. A 2.5 dataset consisting of four equally spaced parallel lines was collected, trimmed, and systematically processed with both 2D and 3D inversion routines. The results were in good agreement with known underground features, and for the present dataset, an iteratively reweighted least squares 2D inversion was clearly preferable over a 3D inversion. This conclusion is based on differences in model resolution, data processing costs, and the value of the final product for engineering decision‐making.