Modellierung Tsunami induzierter Transportvorgänge von groben Gesteinsablagerungen , Kombination physikalischer Versuche, innovativer numerischer Modellierung und Felduntersuchungen
Zusammenfassung der Projektergebnisse
In this project, the influence of non-idealized boulder shapes on boulder transport by a tsunami was investigated for the first time, besides a range of other relevant parameters. The shapes turned out to be decisive parameter for transport or non-transport, in the extremes case. In the course of the evaluation of the physical experiments it became clear that investigations using a range of boulder shapes, e.g., from cubic to flat or more rounded, will be necessary to empirically capture the influence of the boulder shape and to be able to describe it in boulder transport equations. In addition to the influence of the boulder shape, the effects of the coastal bathymetry and topography and, numerically, of sediment load were also investigated. With respect to the stepped coastline, it could be shown that on stepped cliff coasts a slowing down effect of the boulder can occur, which hinders the boulder transport by wave reflection. The numerical boulder transport model developed within the project supports the results of the physical model tests. The influence of the boulder shape and its orientation to the wave could be clearly shown. First investigations concerning the influence of sediment load indicate that an increased average density of the attacking wave leads to a faster acceleration and increased maximum velocity of the boulder. Supplementary numerical investigations based on the SPH method showed that it is not possible with the version of DualSPHysics available during the project period to accurately reproduce the physical model tests. However, due to the rapid developments in the field of the SPH method in general and with respect to the program DualSPHysics in particular, SPH seems to be a promising method for hybrid modelling of small- and medium-scale physical boulder transport experiments. In the context of the project, extensive literature studies were carried out which showed that the published studies on physical model experiments lack comparability, because of the varying ratios between wave and boulder height or the diverging placement of measuring instruments, for example. Concepts for standardization were developed and published in leading scientific journals. In addition, a support tool was developed to help researchers assess the accuracy of the analytical boulder transport equations available today. Based on the results obtained in the project, the numerical boulder transport model should first be validated and calibrated on the basis of physical model experiments in a subsequent step. Afterwards, the model can be coupled with GIS applications. With respect to physical model tests, a unified approach to setting up the model tests within the research community should be sought. Furthermore, in order to empirically capture the influence of boulder shape, studies should be conducted using multiple idealized boulder shapes with gradual variation in complexity.
Projektbezogene Publikationen (Auswahl)
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(2017): Physical modelling of tsunami-induced boulder transport. 03–07 Sep 2017: 5th International Tsunami Field Symposium, Lisbon, Portugal
Jan Oetjen, M. Engel, S.P. Pudasaini, H. Schüttrumpf, H. Brückner
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2017. Enhanced field observation based physical and numerical modelling of tsunami induced boulder transport – Phase 1: physical experiments. Coastal Engineering Proceedings 35, management4
Oetjen, J., Engel, M., Pudasaini, S.P., Schüttrumpf, H.
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(2018): Simulation of boulder transport in a flume comparing cuboid and complex-shaped boulder models. European Geoscience Union (EGU) General Assembly, Vienna. Geophysical Research Abstracts 20, EGU2018-12124
Jan Oetjen, Max Engel, Joschka J. Schönberger, Shiva P. Pudasaini, Holger Schüttrumpf
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(2019): Tsunami boulder transport simulated in a numerical two-phase mass flow model and flume experiments – a combined approach. 25–31 Jul 2019, 20th INQUA Congress, Dublin, Ireland
Jan Oetjen, Max Engel, Holger Schüttrumpf, Shiva P. Pudasaini
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2020. Experimental models of coarse-clast transport by tsunamis. In: Engel, M., Pilarczyk, J., May, S.M., Brill, D., Garrett, E.G. (eds.), Geologi cal records of tsunamis and other extreme waves. Elsevier, Amsterdam, pp. 585–615
Oetjen, J., Engel, M., Schüttrumpf, H.
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2020. Geological records of tsunamis and other extreme waves – concepts, applications and a short history of research. In: Engel, M., Pilarczyk, J., May, S.M., Brill, D., Garrett, E.G. (eds.), Geological records of tsunamis and other extreme waves. Elsevier, Amsterdam, pp. 3–20
Engel, M., May, S.M., Pilarczyk, J., Brill, D., Garrett, E.
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2020. Significance of boulder shape, shoreline configuration and pre-transport setting for the transport of boulders by tsunamis. Earth Surface Processes and Landforms 45, 2118–2133
Oetjen, J., Engel, M., Pudasaini, S.P., Schüttrumpf, H.
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(2021): Significance of boulder shape for the transport of boulders by tsunamis. European Geoscience Union (EGU) General Assembly, Vienna. EGU General Assembly 2021, EGU21-8583
Jan Oetjen, Max Engel, Holger Schüttrumpf
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2021. A review on onshore tsunami deposits along the Atlantic coasts. Earth-Science Re views 212, 103441
Costa, P.J.M., Dawson, S., Ramalho, R., Engel, M., Dourado, F., Bosnic, I., Andrade, C.
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2021. Experiments on tsunami induced boulder transport – a review. Earth-Science Review 220, 103714
Oetjen, J., Engel, M., Schüttrumpf, H.
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2021. Tsunami-like flow induced force on the structure: Prediction formulae for the horizontal force in quasi-steady flow phase. Coastal Engineering 168(4)
Selvam, H., Sriram, V., Schüttrumpf, H., Sannasiraj, S.A.
