Stability analysis of Baishuihe landslide under the combined effect of reservoir and rainfall

Reservoir drawdown and rainfall have important influence on bank landslides, but existing research on these two factors is too idealistic. A new reservoir drawdown model was proposed for the rapid drawdown stage based on the consideration of reduction, navigation and power generation. A rainfall model was proposed considering actural rainfall and rainfall time based on fifty years of daily rainfall data. At last, taking Baishuihe landslide as an example, the landslide stability was analyzed under the combined influenced of rainfall and reservoir drawdown. Results show that the Baishuihe landslide is mainly influenced by reservoir drawdown. The terminal reservoir drawdown model can reduce the effect of continuous decline of reservoir on landslide and the stability decreases about 0.7%~1.2% compared with normal scenario. The reservoir drawdown model proposed in this paper is of significance to the reservoir operation in the Three Gorges Reservoir.

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Stability Analysis of Accumulation Landslides in the Three Gorges Reservoir Area Under Reservoir Water Level Fluctuation Based on Multi-Circular Model

10.21203/rs.3.rs-1075887/v1 ◽

2021 ◽

Author(s):

Zhiqiang Fan ◽

Yanhao Zheng

Keyword(s):

Stability Analysis ◽

Water Level ◽

Three Gorges Reservoir ◽

Three Gorges ◽

Reservoir Water ◽

Reservoir Water Level ◽

Landslide Stability ◽

Slip Surfaces ◽

The Three Gorges ◽

The Stability

Abstract In the Three Gorges Reservoir (TGR) area, the accumulation landslide characterized by stepped slip surfaces is widely developed, and its stability is significantly affected by the fluctuation of reservoir water level. In this paper, the Shuping landslide, a typical accumulation landslide in the TGR area, was selected to study the effect of water level fluctuations on landslide stability. Based on Multi-Circular (M-C) model, it is found that the decline of reservoir water level was the dominant factor causing the decrease of landslide stability. At the end of the decline of reservoir water level, the landslide stability was minimum and the corresponding moment was the most dangerous. The effect of the drawdown speed of reservoir water level on the minimum value of landslide stability had a threshold effect, although the minimum stability coefficient of landslide decreased with the increase of drawdown speed. Under the most dangerous water level conditions, the stability of the piled landslide increased linearly with the increase of the net thrust of piles. Also, by comparing with other classical models, the effectiveness of the M-C model in evaluating landslide stability under the dynamic changes of reservoir water level was verified. The results could provide a reliable scientific basis for improving the stability analysis and reinforcement measures of the accumulation landslide with the multi-circular slip surfaces in the TGR area, as well as can be applied to similar landslides in reservoir areas.

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Stability and Deformation Analysis of Landslide under Coupling Effect of Rainfall and Reservoir Drawdown

Civil Engineering Journal ◽

10.28991/cej-2021-03091713 ◽

2021 ◽

Vol 7 (7) ◽

pp. 1098-1111

Author(s):

Muhammad Shoaib ◽

Wang Yang ◽

Yang Liang ◽

Gohar Rehman

Keyword(s):

Coupling Effect ◽

Field Investigation ◽

Deformation Analysis ◽

Three Gorges ◽

Reservoir Water ◽

Reservoir Water Level ◽

Seepage Analysis ◽

Landslide Stability ◽

Reservoir Drawdown ◽

The Stability

Landslides, a devastating hazard, continue to happen, affecting the lives of thousands of people each year. Fluctuation in the Reservoir Water Level (FRWL) is one of the leading features disturbing the slope stability in reservoir areas, drawdown is more crucial than the rise to the stability of landslide. Latest studies grounded on field investigation and monitoring data propose that landslides in reservoir areas are initiated not solely by one issue like precipitation or FRWL, however conjointly by their joint actions. Zhulinwan landslide in Chongqing, China, Three Gorges Reservoir (TGR) area was analyzed by field investigation and numerical modelling to evaluate the characteristics of the landslide. The changes in landslide stability and deformation under the effect of reservoir drawdown and rainfall is analyzed using GEOSLOPE Software. The seepage analysis is done using SEEP W Model, afterward deformation and stability analysis using SLOPE W and SIGMA W respectively. The analysis confirmed that the coupling effect of reservoir drawdown at 1.2 m/d and rainstorm of once in 50 years return period makes the landslide unstable. Moreover, deformation at the same condition is maximum 0.049 m. The findings may be used by local authorities to help make decisions about slope stabilization in the event of a confirmed significant rainfall event. Doi: 10.28991/cej-2021-03091713 Full Text: PDF

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Regulation of Laijiapu Waterway in Jingjiang Reach

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.2001 ◽

2014 ◽

Vol 501-504 ◽

pp. 2001-2006

Author(s):

Ya Liu ◽

Li Zheng ◽

Cheng Tao Huang ◽

Zhao Biao Huang ◽

Lin Liu

Keyword(s):

Yangtze River ◽

Three Gorges Reservoir ◽

Three Gorges ◽

The Yangtze River ◽

Point Bar ◽

The Three Gorges Reservoir ◽

The Three Gorges ◽

Before And After ◽

The Stability ◽

Channel Bar

After impoundment of the Three Gorges Reservoir, Jingjiang reach, in the middle of the Yangtze River, has gradually shown a series of atypical fluvial features, adversely affecting the maintenance of waterways. Citing the Laijiapu Waterway, a meandering segment in the lower Jingjiang for example, this paper compared the fluvial features of the channel before and after the impoundment, summed up its navigation-obstructing features, and proposed guarding the point bar on the convex bank and channel bar in the widening section as a key to maintaining the stability of the navigation channels.

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