15 May 2024
10:30
Louvain-la-Neuve
Place des Sciences, auditorium A.02 SCES
Landslide dams are natural dams that are formed by the blockage of a river channel with landslides, rock falls and debris flows. Landslide dams are prone to overtopping failure shortly after their formation, resulting in catastrophic floods in the downstream areas, further posing a great danger to the local residents and altering the local environment. Unlike artificial dams and earthen embankments, landslide dams can be characterized by the following three features: the greater dam width along the river, the widely graded and non-uniform material composition, and the internal multi-layered structure. These three characteristics significantly influence the failure of landslide dams and induced morphological changes, but are rarely considered in current research, especially the latter two of them.
The present thesis aims to analyze the failure of landslide dams, as well as the induced floods and morphological changes. The study starts with a field investigation and case study of the two successive landslide dams that occurred in China in 2018. Then, a series of experiments considering widely graded and non-uniform sediments are carried out to analyze the influence of both the dam and movable bed materials on the dam failure process and the induced morphological changes. Furthermore, a numerical model considering the non-uniform and multi-layered sediments is developed based on the shallow water equations, modified Exner equations and Hirano’s active layer equation. The applicability and accuracy of the model are further verified by two experimental tests considering both uniform and non-uniform, single-layer and multi-layer sediments. Finally, the proposed numerical model is applied to simulate the failure of the Baige landslide dam, as well as the induced floods and morphological changes.
This thesis provides new insights into the failure of landslide dams and their impact on local areas. The numerical model developed in this thesis can also serve as a tool to better simulate such events and aid in hazard management.
Jury members :
- Prof. Sandra Soares-Frazao (UCLouvain, Belgium), supervisor
- Prof. Zhenming Shi (Tongji University, China), supervisor
- Prof. Aude Simar (UCLouvain, Belgium), chairperson
- Prof. Donatella Termini (University of Palermo, Italy)
- Prof. Hadrien Rattez (UCLouvain, Belgium)
- Prof. Pieter Rauwoens (KU Leuven, Belgium)
- Prof. Hongchao Zheng (China University of Geoscience, China)