Mobility of slope movements with erosion: Proof-of-concept and application - Part II: Experimental verification


Project management:      Dr.-Ing. Ivo Baselt

                                                    E-mail: ivo.baselt@unibw.de, Tel.: 089/6004-3844

Project engineer:                Dr. rer. nat. Katharina Wetterauer M.Sc.

                                                    E-mail: katharina.wetterauer@unibw.de, Tel.: 089/6004-2479

Running time:                      01.12.2023 – 01.12.2026

Promotion:                            Deutsche Forschungsgemeinschaft (DFG)

Project number:                  522201978

Projektpartner:                 Technische Universität München,

                                                    Dr. Shiva P. Pudasaini, Prof. Dr. Michael Krautblatter                     

Further links:                     DFG - Detailseite

Project description:   

Erosion can significantly increase the destructive force of slope movements by increasing the volume, mobility and force of impact. The hazard potential is directly related to mobility. So far, there is no clear mechanical approach to predict how much energy slope movements gain or lose due to erosion. Only the new mechanical model for the energy budget of erosive slope movements offers a statement about the changed mobility (Pudasaini & Krautblatter, 2021). This fundamentally new understanding demonstrates that the increased inertia of the slope movement is related to a “material uptake velocity”. Thus, the true inertia of erosive slope movements can be calculated, a breakthrough in the correct determination of their mobility. We have thus shown how the “erosion velocity” regulates the energy budget of slope movements and determines whether their mobility increases or decreases. This also depends on the developed energy generator, which for the first time allows a mechanical quantification of erosion energy and a precise description of mobility. This answers the long-standing question of why many erosive slope movements generate higher mobility, while others reduce mobility. It was also shown that the removal of grains (erosion) and their entrainment are fundamentally different processes. The energy of slope movements is only increased and their mobility enhanced if the erosion velocity is greater than the material uptake velocity. The energy velocity delineates three excess energy regimes: positive, negative and zero. We have thus demonstrated that the existing flow models are physically and mathematically incorrect when erosion is taken into account. Even if we correctly include the erosion-induced net momentum production with the dynamic equations, it is imperative that these are verified with laboratory experiments and validated with field events in order to be used for predictions. We aim to prove that the new physical principles presented in Pudasaini & Krautblatter (2021) on the mechanics of erosion-induced mobility of slope movements can be implemented. We will perform pioneering experimental work and pursue novel approaches to explore, verify and demonstrate the practical applicability of erosive slope movements with simulations (Fig.1). This will be the first complete and scientifically sound description of the complex entrainment phenomena and mobility of multiphase erosive slope movements. This will be a very useful and unique tool for the application and prediction of slope movements and mitigation of the natural hazards they generate.

AbbildungInternetseite_Mure_IB_KW.bmp

Fig.1: Examples of experimental simulation of slope movements (Baselt et al., 2021).