Print Email Facebook Twitter Geophysical tomography as a tool to estimate the geometry of soil layers Title Geophysical tomography as a tool to estimate the geometry of soil layers: relevance for the reliability assessment of dikes Author Chavez Olalla, J.F. (TU Delft Geo-engineering) Winkels, T. G. (Universiteit Utrecht) Ngan-Tillard, D.J.M. (TU Delft Geo-engineering) Heimovaara, T.J. (TU Delft Geoscience and Engineering) Department Geoscience and Engineering Date 2021 Abstract The geometric variability of soil layers is a large source of uncertainty in the reliability assessment of dikes. Because direct samples of the subsurface soils are often insufficient to capture the complexity of the subsurface, geophysical methods provide a powerful source of complementary information. A combined approach to estimate the geometry of soil layers is presented. The approach combines local point data, i.e. data obtained from a CPT or a borehole log, and geophysical tomography in a universal cokriging framework. The approach uses the contact points between soil layers obtained from local point data and the orientations of the layers derived from geophysical tomography. To reduce subjectivity in the interpretation of tomographic images, an automated edge detection technique was used. The combined approach was applied to characterise two test sites where the presence of paleochannels locally change the geometry of soil layers. The results show that a combined approach enables the reduction of sampling efforts with an improved estimation of geometric variability. Subject dike reliabilityedge detectionGeometric variabilitygeophysical tomographyuniversal cokriging To reference this document use: http://resolver.tudelft.nl/uuid:1790e400-0415-455d-b5bd-85189fe9910b DOI https://doi.org/10.1080/17499518.2021.1971252 ISSN 1749-9518 Source Georisk: assessment and management of risk for engineered systems and geohazards, 16 (4), 678-698 Part of collection Institutional Repository Document type journal article Rights © 2021 J.F. Chavez Olalla, T. G. Winkels, D.J.M. Ngan-Tillard, T.J. Heimovaara Files PDF Geophysical_tomography_as ... _dikes.pdf 10.2 MB Close viewer /islandora/object/uuid:1790e400-0415-455d-b5bd-85189fe9910b/datastream/OBJ/view