A Finite Element Model for the Analysis of Seepage Flow of Water Under Concrete Dams.

Seepage analysis plays a key role in geotechnical engineering and contributes significantly to the success of its infrastructure projects. Several engineers consider the Finite element (FE) method basics when executing calculations for designing hydraulic structures and dams. Numerical methods are used herein to solve the problem of seepage flow of water under concrete dams. The FE method is applied to model the dam structure and water level. The seepage velocity distribution in the porous soil is determined, and the effects of varying multiple parameters on the velocity are studied. The different parameters investigated are the dam dimensions (i.e., width (4,8,10,15 m) and depth (0,2,4,8 m)), upstream water head level (10, 15, 20 m), soil permeability (10, 15, 20 m day⁻¹) and ambient temperature (5 °C and 50 °C). The developed FE models were validated by carrying out comparisons with analytical solutions that showed that they were in good agreement. It was found that the dam width is inversely proportional to the seepage rate and is independent of the water head level where increasing the dam by 1 unit width drops the seepage by 3.7% regardless of the water head levels. The depth of the dam is exponentially related to the distance away from the toe and independent of both the dam's width and water head level. Increasing the dam depth reduces the seepage flow by 73% at shallower depths and the effect minimizes as we increase the depth to 1% reduction in seepage simulating an exponential behavior. Such behavior is typical for the dam depth factor regardless of the dam width and water head level variations used in the study. The water head level was also found to be linearly proportional to the seepage flow rate with an increased effect of about 10% per additional 1-m head level. In addition, the soil permeability is linearly proportional to the seepage rate, and the same increment is obtained regardless of the dam's dimensions and water head level. The effects of ambient temperature on the seepage flow were introduced in this paper and will be further studied in detail in our future simulations. Our study concludes that the developed FE model can predict the seepage flow of water under concrete dams with a reasonable level of accuracy. [ABSTRACT FROM AUTHOR]