Numerical Modeling of Pore Water Pressure Development within a Thin Clay Core in an Earth Dam

The representativeness of measurements monitored in earth dams is analysed to investigate how a given measured quantity can be used to interpret the dam's mechanical behaviour. Representativeness is evaluated on the basis of spatial continuity of the measured quantity and the sensitivity of that quantity to natural mechanical nonhomogeneity. The discussion is supported by results from case studies and numerical examples. The study is mainly focused on pore-water pressure measurements. Spatial continuity of pore-water pressure is analysed with consideration of both saturation and drainage conditions. The paper discusses how pore-water pressure representativeness can vary over the lifetime of the dam.Key words: earth dam, pore-water pressure, monitoring.

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Laboratory Experiment and Numerical Analysis on the Precursory Hydraulic Process of Rainfall-Induced Slope Failure

Advances in Civil Engineering ◽

10.1155/2020/2717356 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Joon-Young Park ◽

Young-Suk Song

Keyword(s):

Numerical Modeling ◽

Laboratory Test ◽

Water Content ◽

Pore Water ◽

Slope Failure ◽

Pore Water Pressure ◽

Water Pressure ◽

Volumetric Water Content ◽

Wetting Front ◽

Artificial Rainfall

A combined analysis involving a laboratory test and numerical modeling was performed to investigate the hydraulic processes leading to slope failure during rainfall. Through a laboratory landslide test in which artificial rainfall was applied to a homogeneous sandy slope, the timing and configurations of multiple slides were identified. In addition, volumetric water content was measured in real time through the use of monitoring sensors. The measured volumetric water content data were then used to validate the relevance of the numerical modeling results. The validated numerical modeling of the laboratory-scale slope failures provided insight into the hydraulic conditions that trigger landslides. According to the numerical modeling results, the miniaturized slope in the laboratory test was saturated in a manner so that the wetting front initially progresses downward and then the accumulated rainwater at the toe of the slope creates a water table that advances toward the crest. Furthermore, each of the five sequential failures that occurred during this experiment created slip surfaces where the pore-water pressure had achieved full saturation and an excessive pore-water pressure state. The findings of this study are expected to help understand the hydraulic prerequisites of landslide phenomena.

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An Investigation on performance of the cut off wall and numerical analysis of seepage and pore water pressure of Eyvashan earth dam

Iranian Journal of Science and Technology Transactions of Civil Engineering ◽

10.1007/s40996-021-00613-y ◽

2021 ◽

Author(s):

Behrang Beiranvand ◽

Mehdi Komasi

Keyword(s):

Numerical Analysis ◽

Pore Water ◽

Pore Water Pressure ◽

Water Pressure ◽

Earth Dam ◽

Coefficient Of Determination ◽

Correct Operation ◽

Seepage Rate ◽

Reservoir Conditions ◽

Good Agreement

AbstractOne of the most important issues in earth dams is the control rate of seepage from the foundation and dam bodies. Due to the site of the dams, to increase the creep length and reduce the seepage, there are several methods for sealing the reservoir of dams that construction of the cut-off wall under the clay core of the dams is one of the most effective methods. In this study, the seepage rate and pore water pressure of the Eyvashan earth dam, comparison of instrument results with the results of numerical analysis and, finally, the performance of the cut-off wall are investigated. According to the results of instrumental and numerical analysis, the maximum seepage rate in full reservoir conditions is equal to 831,604 m3/year. To fit the data of instrumentation and numerical analysis, multivariate regression was used and the coefficient of determination was used which R2 = 0.9892 and R2 = 0.9834, respectively, were obtained for seepage and pore water pressure. Very good agreement between the results of the observed data and the predicted data indicates the proper behavior of the dam in terms of pore water pressure. Also, due to the results of numerical simulation and instrumentation, the pore water pressure in the downstream part of the cut-off wall is suddenly dropped, which indicates the correct operation of the cut-off wall.

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