@inproceedings{HombergBaumProhaskaetal.2012, author = {Homberg, Ulrike and Baum, Daniel and Prohaska, Steffen and Kalbe, Ute and Witt, Karl Josef}, title = {Automatic Extraction and Analysis of Realistic Pore Structures from µCT Data for Pore Space Characterization of Graded Soil}, series = {Proceedings of the 6th International Conference on Scour and Erosion (ICSE-6)}, booktitle = {Proceedings of the 6th International Conference on Scour and Erosion (ICSE-6)}, pages = {345 -- 352}, year = {2012}, language = {en} } @inproceedings{SeblanyHombergVincensetal., author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for the definition of a local pore and the CSD computation of granular materials}, series = {Proceedings of the 25th meeting of the Working Group on Internal Erosion in embankment dams and their foundations}, booktitle = {Proceedings of the 25th meeting of the Working Group on Internal Erosion in embankment dams and their foundations}, publisher = {Deltares}, address = {Delft, Netherlands}, isbn = {978-90-827468-1-5 | 978-90-827468-0-8}, pages = {150 -- 159}, language = {en} } @misc{SeblanyHombergVincensetal., author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for the definition of a local pore and the CSD computation of granular materials}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-67069}, language = {en} } @article{VincensWittHomberg2015, author = {Vincens, Eric and Witt, Karl Josef and Homberg, Ulrike}, title = {Approaches to Determine the Constriction Size Distribution for Understanding Filtration Phenomena in Granular Materials}, series = {Acta Geotechnica}, volume = {10}, journal = {Acta Geotechnica}, number = {3}, publisher = {Springer}, doi = {10.1007/s11440-014-0308-1}, pages = {291 -- 303}, year = {2015}, language = {en} } @inproceedings{SemarBinnerHombergetal.2009, author = {Semar, Olivier and Binner, Richard and Homberg, Ulrike and Kalbe, Ute and Mehlhorn, Tobias and Prohaska, Steffen and Slowik, Volker and Witt, Karl Josef}, title = {Conditions for Suffosive Erosion Phemomena in Soils - Concept and Approach}, series = {Workshop Internal Erosion}, volume = {21}, booktitle = {Workshop Internal Erosion}, pages = {29 -- 35}, year = {2009}, language = {en} } @misc{VincensWittHomberg2014, author = {Vincens, Eric and Witt, Karl Josef and Homberg, Ulrike}, title = {Approaches to Determine the Constriction Size Distribution for Understanding Filtration Phenomena in Granular Materials}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-43960}, year = {2014}, abstract = {Granular filters in hydraulically loaded earth structures constitute the ultimate barrier for the blockage of small particles moving through the structure regularly or along concentrated leaks. If filters are inefficient to block small particles several types of internal erosion may be initiated. A corresponding phenomenon appears during suffusion in a wide graded hydraulically loaded fill, when fine particles, embedded in the pore structure of a soil skeleton, are washed out. The cumulative constriction size distribution (CSD) is physically the key property that qualifies the soils retention capability as like a spatial acting sieve. Constrictions are defined as the narrowest sections of channels between larger volumes (pores) within the pore network of granular material and they are the main obstacles for a small particle to overcome when flowing along pathways. At least three different approaches are available to determine and compute the CSD, i.e. experimental, numerical and analytical methods. The purpose of this review is to present and discuss these methods pointing out their limits, advantages and significance related to internal erosion phenomena.}, language = {en} } @inproceedings{BinnerHombergProhaskaetal.2010, author = {Binner, Richard and Homberg, Ulrike and Prohaska, Steffen and Kalbe, Ute and Witt, Karl Josef}, title = {Identification of Descriptive Parameters of the Soil Pore Structure using Experiments and CT Data}, series = {Proceedings of the 5th International Conference on Scour and Erosion (ICSE-5)}, booktitle = {Proceedings of the 5th International Conference on Scour and Erosion (ICSE-5)}, publisher = {American Society of Civil Engineers (ASCE)}, pages = {397 -- 407}, year = {2010}, language = {en} } @article{SeblanyHombergVincensetal., author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for defining pores and constrictions in numerical packing of spheres}, series = {Granular Matter}, volume = {20}, journal = {Granular Matter}, number = {37}, publisher = {Springer Berlin Heidelberg}, issn = {1434-5021}, doi = {10.1007/s10035-018-0808-z}, abstract = {The void space of granular materials is generally divided into larger local volumes denoted as pores and throats connecting pores. The smallest section in a throat is usually denoted as constriction. A correct description of pores and constrictions may help to understand the processes related to the transport of fluid or fine particles through granular materials, or to build models of imbibition for unsaturated granular media. In the case of numerical granular materials involving packings of spheres, different methods can be used to compute the pore space properties. However, these methods generally induce an over-segmentation of the pore network and a merging step is usually applied to mitigate such undesirable artifacts even if a precise delineation of a pore is somewhat subjective. This study provides a comparison between different merging criteria for pores in packing of spheres and a discussion about their implication on both the pore size distribution and the constriction size distribution of the material. A correspondence between these merging techniques is eventually proposed as a guide for the user.}, language = {en} } @misc{SeblanyHombergVincensetal., author = {Seblany, Feda and Homberg, Ulrike and Vincens, Eric and Winkler, Paul and Witt, Karl Josef}, title = {Merging criteria for defining pores and constrictions in numerical packing of spheres}, issn = {1438-0064}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-69158}, abstract = {The void space of granular materials is generally divided into larger local volumes denoted as pores and throats connecting pores. The smallest section in a throat is usually denoted as constriction. A correct description of pores and constrictions may help to understand the processes related to the transport of fluid or fine particles through granular materials, or to build models of imbibition for unsaturated granular media. In the case of numerical granular materials involving packings of spheres, different methods can be used to compute the pore space properties. However, these methods generally induce an over-segmentation of the pore network and a merging step is usually applied to mitigate such undesirable artifacts even if a precise delineation of a pore is somewhat subjective. This study provides a comparison between different merging criteria for pores in packing of spheres and a discussion about their implication on both the pore size distribution and the constriction size distribution of the material. A correspondence between these merging techniques is eventually proposed as a guide for the user.}, language = {en} }