Effects of soil properties and geomorphic parameters on the breach mechanisms of landslide dams and prediction of peak discharge
(2023) Acta Geotechnica — Vol. 18, n° 2, p. 5485-5502 (2023)
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2023-Effectsofsoilpropertiesandgeomorphicparametersonthebreachmechanismsoflandslidedamsandpredictionofpeakdisc.pdf
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- Authors
- et. al.
- Abstract
- Breaching of a dam depends on the complex interaction between the dam and the backwater lake. Here, we conduct a series of experiments to investigate the failure mechanisms of landslide dams by considering debris composition and geomorphic parameters (dam height and lake volume), discern the failure mode and predict peak outflow rates of landslide dams in the field and in model tests. The failure modes of landslide dams are regulated by soil properties such as the shear strength and seepage. Failures of fine-grained and widely graded dams are induced by overtopping along with seepage instability and headcutting, respectively. Coarse-grained dams remain stable. Geomorphic parameters of dams govern the infilling time and affect the failure modes by the seepage. Seepage significantly reduces the stability of fine-grained dams and changes breach evolution and duration, while its effect on widely graded and coarse-grained dams is weak. Peak outflow rates of fine-grained dams are larger than those of widely graded dams with the same dam height due to larger breach depths and erosion rates. The peak outflow rate and breach duration are more related to the breach depth than the dam height because the influence of soil properties is considered in the former. Peak outflow rates of landslide dams are well predicted by a regression analysis with the lake volume, dam height and soil properties. Our results facilitate the understanding of breach mechanisms of landslide dams and prediction of peak outflow rates based on dam parameters.
- Affiliations
Tongji University
Citations
Guan, S., Shi, Z., Zheng, H., Shen, D., Kevin J. Hanley, Yang, J., & et al. (2023). Effects of soil properties and geomorphic parameters on the breach mechanisms of landslide dams and prediction of peak discharge. Acta Geotechnica, 18(2), 5485-5502. https://doi.org/10.1007/s11440-023-01908-2 (Original work published 2023)