scholarly journals Study on the Hydraulic Parameters of Woshaxi Landslide Soils during Water Level Drawdown of Three Gorges Reservoir

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Zhenhua Zhang ◽  
Xiaoyu Huang ◽  
Wu Liu ◽  
Liang Wang
Keyword(s):  
Slope Stability ◽  
Three Gorges Reservoir ◽  
Soil Samples ◽  
Hydraulic Parameters ◽  
Three Gorges ◽  
Permeability Test ◽  
Reservoir Water ◽  
Analysis And Evaluation ◽  
Unsaturated Permeability ◽  
Soil Water Characteristic Curves

Variation of hydraulic parameters for unsaturated soil in bank slopes during reservoir water rising or falling process is crucial to scientific analysis and evaluation of bank slope stability. In this paper, soil samples from the Woshaxi landslide in the Three Gorges Reservoir were taken for a permeability test under reservoir drawdown conditions using an independently developed apparatus, which can simulate the variation process of internal seepage in bank slope soils. Changes of particle gradations, soil-water characteristic curves, and unsaturated permeability functions of the soil samples during reservoir falling process were studied by combining with the physical empirical model and numerical simulation. Permeability test results show that fine particles in soil samples migrated and were lost under seepage force action during the tests, leading to a continuous decrease of fine particle content indicated in the grain size distribution curves, in which particles with a size less than 0.02 mm lose the most. As permeation time increases, the soil saturated permeability enhances constantly with the change rate increasing first and then decreasing. The soil-water characteristic curves change obviously in the high matrix suction section (10~104 kPa), and the volumetric water content decreases constantly and shows a positive correlation with the fine particle content. During the permeability test, the unsaturated permeability coefficient corresponding to a fixed matric suction increases with the drawdowns of the reservoir water level. Slope stability results show that neglecting the variational characteristics of hydraulic parameters in slope stability evaluation can result in a bigger safety factor, which is dangerous for slope safety evaluation. The research results can provide a scientific basis for the stability analysis and evaluation of the bank slopes in the Three Gorges Reservoir Area.

Water Environment Risk Assessment System and Practice of Management for the Three Gorges Reservoir Based on List Method

2011 ◽  
Vol 71-78 ◽  
pp. 4288-4292
Author(s):  
Li Ping Guo ◽  
Ju Mei Liu ◽  
Shuang Kou Chen
Keyword(s):  
Risk Assessment ◽  
Environmental Risk ◽  
Three Gorges Reservoir ◽  
Water Environment ◽  
Assessment System ◽  
Three Gorges ◽  
Reservoir Water ◽  
The Three Gorges Reservoir ◽  
Industrial Enterprises ◽  
The Three Gorges

In view of the water impact of environmental risk of industrial enterprises in the Three Gorges Reservoir, based on the existing methods of water environmental risk assessment and integrated the Germany detailed list assessment method; we have established a brand-new index system which could meet with the Three Gorges Reservoir water environment risk evaluation, and the system has the feature of quantitative indicators and risk classification. Site Case analysis showed that: evaluation results and the qualitative judgment are on the spot consistent with the environment Supervisory department, which demonstrated that the risk assessment system is reasonable and has easier operability. Meanwhile the system could help the enterprise and the environment Supervisory department to investigate water environment hidden danger, reduce the enterprise water environment risk effectively and provide the scientific basis for the environment Supervisory management's decision-making and the management.

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

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.

scholarly journals The Coupling Effect of Rainfall and Reservoir Water Level Decline on the Baijiabao Landslide in the Three Gorges Reservoir Area, China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Nenghao Zhao ◽  
Bin Hu ◽  
Qinglin Yi ◽  
Wenmin Yao ◽  
Chong Ma
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
Coupling Effect ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Reservoir Area ◽  
The Three Gorges ◽  
Water Level Decline

Rainfall and reservoir level fluctuation are two of the main factors contributing to reservoir landslides. However, in China’s Three Gorges Reservoir Area, when the reservoir water level fluctuates significantly, it comes at a time of abundant rainfall, which makes it difficult to distinguish which factor dominates the deformation of the landslide. This study focuses on how rainfall and reservoir water level decline affect the seepage and displacement field of Baijiabao landslide spatially and temporally during drawdown of reservoir water level in the Three Gorges Reservoir Area, thus exploring its movement mechanism. The monitoring data of the landslide in the past 10 years were analyzed, and the correlation between rainfall, reservoir water level decline, and landslide displacement was clarified. By the numerical simulation method, the deformation evolution mechanism of this landslide during drawdown of reservoir water level was revealed, respectively, under three conditions, namely, rainfall, reservoir water level decline, and coupling of the above two conditions. The results showed that the deformation of the Baijiabao landslide was the coupling effect of rainfall and reservoir water level decline, while the latter effect is more pronounced.

Experimental Study on the Strength Difference of Two Types of Sandstones With Different Composition of Minerals Under the Conditions of Dry and Wet Cycles

2011 ◽  
Vol 374-377 ◽  
pp. 2217-2220
Author(s):  
Zhen Hua Zhang ◽  
Jing Jing Xue ◽  
Hua Yan Yao
Keyword(s):  
Compressive Strength ◽  
Three Gorges Reservoir ◽  
Three Gorges Reservoir Area ◽  
Type I ◽  
Type Ii ◽  
Three Gorges ◽  
Reservoir Water ◽  
Strength Difference ◽  
Composition Of Minerals ◽  
Wet And Dry Cycles

Some rock slides have taken place in Three Gorges Reservoir Area, China. Many Researches on the causes of the slides shows that the more sensitive of rock strength to the reservoir water level fluctuation, the easier to fail of the rock slopes. In order to study the strength difference of different sandstones in reservoir water fluctuation zone of Three Gorges Reservoir, the authors taken two types of sandstones with different composition of minerals as a typical case to study in detail. One type of the two sandstones (called Type I) is composed of quartz, feldspar, muscovite and calcite, argillaceous cement. The other (called Type II) is composed of quartz, feldspar, sericite, argillaceous cement. Uniaxial compression tests indicate that the compressive strength of type I sandstone decreased significantly as they underwent first wet and dry cycle, and then nearly kept constant when they underwent the following wet and dry cycles, and that the compressive strength of Type II sandstones nearly kept constant when they underwent many times of wet and dry cycles.

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