Back to Search
Start Over
The Impact of Reservoir Fluctuations on Reactivated Large Landslides: A Case Study
- Source :
- Geofluids, Vol 2019 (2019)
- Publication Year :
- 2019
- Publisher :
- Hindawi Limited, 2019.
-
Abstract
- Filling of Xiangjiaba Reservoir Lake in the Southwest China triggered and reactivated numerous landslides due to water fluctuation. In order to understand the relationship between reservoirs and slope instability, a typical reservoir landslide (Dasha landslide) at the right bank of Jinsha River was selected as a case study for in-depth investigations. The detailed field investigations were carried out to identify the landslide with respect to its surroundings and to find out the slip surface. Boreholes were drilled to find out the subsurface lithology and the depth of failure of Dasha landslide. The in situ geotechnical tests were performed, and the soil samples from exposed slip surface were retrieved for geotechnical laboratory analysis. Finally, stability analysis was done using the 3D strength reduction method under different conditions of reservoir water level fluctuations and rainfall conditions. The in-depth investigations show that the Dasha landslide is a bedding rockslide which was once activated in 1986. The topography of Dasha landslide is relatively flat, while the back scarp and local terrain is relatively steep. The total volume of landslides is about 580×104 m3 with an average thickness of 20 m. Bedrock in the landslide area is composed of Suining Formation of the Jurassic age. The main rock type is silty mudstone with sandstone, and the bedding orientation is 300~310° ∠ 7~22°. The factor of safety (FOS) of Dasha landslide obtained by 3D strength reduction cannot meet the minimum safety requirement under the working condition of reservoir level fluctuation as designed, with effect of rainfall and rapid drawdown.
- Subjects :
- 021110 strategic, defence & security studies
geography
geography.geographical_feature_category
Article Subject
010504 meteorology & atmospheric sciences
Bedding
Lithology
Bedrock
lcsh:QE1-996.5
0211 other engineering and technologies
Borehole
Landslide
02 engineering and technology
Rockslide
Fault scarp
01 natural sciences
lcsh:Geology
Factor of safety
General Earth and Planetary Sciences
Geomorphology
Geology
0105 earth and related environmental sciences
Subjects
Details
- ISSN :
- 14688123 and 14688115
- Volume :
- 2019
- Database :
- OpenAIRE
- Journal :
- Geofluids
- Accession number :
- edsair.doi.dedup.....bc0136279e8869285897ab39753c343f