scholarly journals Comprehensive Assessment of the Effect of Water Pressure on the Development of Cracks in Gravity Concrete Dams

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hamed Safayenikoo
Keyword(s):  
Tensile Strength ◽  
Water Level ◽  
Water Pressure ◽  
Energy Parameter ◽  
Concrete Dams ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Factors Affecting ◽  
Hydraulic Failure ◽  
Safety And Stability

In recent years, extensive studies have been conducted to ensure the safety and stability of concrete dams. The development of numerical methods in considering more factors affecting the response of dams and also increasing the accuracy of calculation methods has played an important role in ensuring the safety of concrete dams. Therefore, one of the most important points in the design and analysis of concrete dams is to predict the location of cracks, expand it, investigate the phenomenon of hydraulic failure, consider the pressure caused by the infiltration of reservoir water into cracks and joints in static and dynamic states, and find solutions prevention of dam destruction due to this phenomenon. In the study of the effect of tensile strength, with increasing tensile strength, the reservoir water level increases at the beginning of cracking and the final reservoir water level increases, but there is no linear relationship between tensile strength and the two responses. In general, in examining the refractive energy parameter in each of the states with and without taking into account the water pressure inside the crack, the results of the mentioned models are slightly different from each other, but comparing the results shows that in nonlinear analysis considering water pressure inside the crack failure energy change has a greater impact on the results of these models.

scholarly journals The Monitoring-Based Analysis on Deformation-Controlling Factors and Slope Stability of Reservoir Landslide: Hongyanzi Landslide in the Southwest of China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Bing Han ◽  
Bin Tong ◽  
Jinkai Yan ◽  
Chunrong Yin ◽  
Liang Chen ◽  
...  
Keyword(s):  
Water Level ◽  
Water Pressure ◽  
Monitoring Program ◽  
Significant Risk ◽  
Controlling Factors ◽  
Seepage Water ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Reservoir Area ◽  
Reservoir Landslide

Reservoir landslide is a type of commonly seen geological hazards in reservoir area and could potentially cause significant risk to the routine operation of reservoir and hydropower station. It has been accepted that reservoir landslides are mainly induced by periodic variations of reservoir water level during the impoundment and drawdown process. In this study, to better understand the deformation characters and controlling factors of the reservoir landslide, a multiparameter-based monitoring program was conducted on a reservoir landslide—the Hongyanzi landslide located in Pubugou reservoir area in the southwest of China. The results indicated that significant deformation occurred to the landslide during the drawdown period; otherwise, the landslide remained stable. The major reason of reservoir landslide deformation is the generation of seepage water pressure caused by the rapidly growing water level difference inside and outside of the slope. The influences of precipitation and earthquake on the slope deformation of the Hongyanzi landslide were insignificant.

Stability of No 7 Landslide Located at Ciha Gorge under the Condition of Reservoir Water Level Rise

2011 ◽  
Vol 368-373 ◽  
pp. 1482-1486
Author(s):  
Yan Hui Song ◽  
Ying Wang ◽  
Min Qi Huang
Keyword(s):  
Shear Strength ◽  
Water Level ◽  
Slip Band ◽  
Water Pressure ◽  
Work Conditions ◽  
Stability Factor ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Stability Calculation ◽  
The Stability

Engineering geology characteristics of No. 7 landslide located at Ciha Gorge is described and shear strength of the slip band soils is determined. Based on the above, unbalanced pushing force method is used to calculate the stability factor of the landslide the under different work conditions. It shows that the influence of the reservoir water level rising on the No. 7 landslide mainly includes two points: (1) water makes the shear strength of slip band soils reduced and thus result in the reduction of the stability factor; (2) the rising of reservoir water level also exerts water pressure to the surface of landslide body, and this is beneficial to landslide stability. Calculation results show that with the rising of reservoir water level the stability factor will experience beginning’s reducing followed by later increasing. The minimum stability factor in the process of impounding is 1.05 and it will be 1.08 when reservoir water level reaches to normal impounded level. This shows that No. 7 landslide will maintain elemental stability status in the all process of impounding.

scholarly journals Experimental and numerical study of upstream slope stability in an earth dam reservoir under rapid drawdown conditions

2020 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Seyed Habib Mousavi Jahromi ◽  
Mansour Pakmanesh ◽  
Amir Khosrojerdi ◽  
Hossein Hassanpour Darvishi ◽  
Hossein Babazadeh
Keyword(s):  
Water Level ◽  
Pore Water Pressure ◽  
Numerical Study ◽  
Water Pressure ◽  
Earth Dam ◽  
Dam Reservoir ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Seepage Analysis ◽  
Upstream Slope

The rapid ‎drawdown of the dam reservoir is one of the most common situations occurring in the lifetime of a dam. For this reason, one of the main factors in the design of the upstream slope is the rapid drainage of the reservoir. In this case, the upstream slope is in a critical condition and the slope may be unstable. When the water surface in the reservoir is drawdown suddenly, the water level in the dam body does not decrease at the same time as the reservoir water level. The analysis of seepage from the earth dam body and calculation of the water loss play an important role in calculating the amount of pore water pressure, and, consequently, the stability analysis of the dam body. In addition, any seepage analysis is dependent on the hydraulic properties of the dam materials. In order to investigate the effect of hydraulic conductivity on the rapid drawdown of water level and the seepage, an experimental model was constructed of an earth dam. By accurate measurement of hydraulic parameters of the materials in saturated and unsaturated media, the flow through this model was modeled using a disk penetrometer by seep/w software. The results were then compared with the observed data.

scholarly journals Fluctuation Effect of Reservoir Water Level on the Seepage of Earth-Fill Dam

2021 ◽  
Vol 9 (6) ◽  
pp. 11-19
Author(s):  
R. Asmaranto ◽  
D. Sisinggih ◽  
R.N.A Rastanto
Keyword(s):  
Water Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Levels ◽  
Water Infiltration ◽  
Seepage Discharge ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Critical Discharge ◽  
Earth Fill

Lots of dam failures are the result of uncontrolled seepage. The collapse of the Situ Gintung Dam in Tangerang, Banten-Indonesia in 2009 due to heavy rains caused the dam structure to collapse. This is due to increased pore water pressure in the landfill. To anticipate collapse due to uncontrolled seepage, it is necessary to monitor it based on the behavior of changes in rainfall and reservoir water levels. Seepage within the dam body is often monitored using instrumentation tools such as standpipe piezometer (standpipe piezometer) or electric piezometer. But often the piezometer cannot work properly because it is clogged, so it cannot monitor the condition of the seepage. Other instrumentations such as V-Notch are also used to measure seepage discharge. This study aims to determine the behavior of changes in the reservoir water level caused by changes in rainfall and its effect on body seepage of the earth-fill Type dam. By knowing the phenomenon of the behavior of the relationship between reservoir water infiltration and rainfall, it will obtain information on rainfall that endangers the dam which will affect the downstream. In this study, a case study of the Selorejo Dam was taken which has a large enough reservoir capacity of about 31 million m3 which is included in the Brantas River Basin. The results showed that 5 piezometers devices were damaged (SL 1, SL 2, SL 4, SL 6, and SL 7) where they could not read the phreatic water level properly, and 2 piezometers were less sensitive to reading fluctuations in reservoir water levels. namely SL 10 and SL 11 which showed R2 values of 29.78% and 39.4%, respectively. While the maximum seepage discharge is recorded at 1474 liters/minute, this is still below the critical discharge of 1630 liters/minute allowed for this dam, but this needs to be a concern, especially the discharge from toe drain from the left side seepage and C-area which is the leakage from the left support pedestal also contributes a larger discharge than other observation points.

scholarly journals Slope stability analysis considering seepage and stress coupling under water level fluctuation

2021 ◽  
Vol 276 ◽  
pp. 01028
Author(s):  
Zhou YiLiang ◽  
Li Ming ◽  
Li ZiLong
Keyword(s):  
Slope Stability ◽  
Water Level ◽  
Factor Of Safety ◽  
Coupling Effect ◽  
Water Pressure ◽  
Water Level Fluctuation ◽  
Level Fluctuation ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Stability Calculation

The reservoir water level fluctuation is an important factor inducing the reaction of pore-water pressure, seepage and at last resulting in instability and failure of the slope. A typical homogeneous slope is conducted as an example in this paper, the seepage and stress coupling effect is considered, and the slope stability calculation and analysis are carried out by using the finite element stress method. The results demonstrate that the factor of safety increases with the reservoir water level rises, and then gradually changes from decrease to stabilization. It should be noted that the factor of safety decreases slightly during the initial stage of water level rising at the speed of 0.2 m/d, which the slope will probably lose its stability. On the other, the factor of safety changes from decrease to increase along with the reservoir water level drawdown, and then gradually tends to stabilization. There is a minimum factor of safety when the water level is at about 1/4 of the slope height, and the minimum factor of safety decreases with increasing drawdown speed, just as the factor of safety decreases from 0.83 to 0.73 when the drawdown speed is increased from 0.20 m/d to 5.0 m/d.

The Analysis about Seepage of the Bank Slope under the Cycle Rising and Drawdown of Reservoir Water Level

2013 ◽  
Vol 353-356 ◽  
pp. 112-115
Author(s):  
Xiao Wen Liu ◽  
Wen Wan ◽  
Xi Zhong Shen
Keyword(s):  
Water Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Bank Slope ◽  
Saturation Region ◽  
Distribution Laws ◽  
Seepage Theory ◽  
Stabilization Period

Bank slope seepage field is analyzed by saturated-unsaturated seepage theory under the three times cycle conditions of water level rising and drawdown . The pore water pressure distribution laws of the water level rising period, the stabilization period, the period of decline and decline stable period for every cycle are researched. The result shows soil near slope region is saturated easily after many rounds of water level rising and drawdown, and saturation region gradually increases. Soil phreatic line near slope falls fastly in the drawdown period, away from the slope, phreatic line declines slowly.

scholarly journals Application of Neural Network Models and ANFIS for Water Level Forecasting of the Salve Faccha Dam in the Andean Zone in Northern Ecuador

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2011
Author(s):  
Pablo Páliz Larrea ◽  
Xavier Zapata Ríos ◽  
Lenin Campozano Parra
Keyword(s):  
Neural Network ◽  
Water Level ◽  
Clustering Algorithm ◽  
Network Models ◽  
Water Levels ◽  
Subtractive Clustering ◽  
Neural Network Models ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Maximum Delay

Despite the importance of dams for water distribution of various uses, adequate forecasting on a day-to-day scale is still in great need of intensive study worldwide. Machine learning models have had a wide application in water resource studies and have shown satisfactory results, including the time series forecasting of water levels and dam flows. In this study, neural network models (NN) and adaptive neuro-fuzzy inference systems (ANFIS) models were generated to forecast the water level of the Salve Faccha reservoir, which supplies water to Quito, the Capital of Ecuador. For NN, a non-linear input–output net with a maximum delay of 13 days was used with variation in the number of nodes and hidden layers. For ANFIS, after up to four days of delay, the subtractive clustering algorithm was used with a hyperparameter variation from 0.5 to 0.8. The results indicate that precipitation was not influencing input in the prediction of the reservoir water level. The best neural network and ANFIS models showed high performance, with a r > 0.95, a Nash index > 0.95, and a RMSE < 0.1. The best the neural network model was t + 4, and the best ANFIS model was model t + 6.

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