A Comparison Between 2D and 3D Seepage Analysis Results in Earth Dams Constructed in Narrow Valleys (Case Study: Haaleh Dam)

摘要

The most common method used in seepage analysis of earth dams is performing a 2D analysis on the maximum cross-section, and generalizing its results to the third dimension. As a normal consequence of this method the effect of the valley shape, and changes in material properties along the third dimension, are ignored. In this research both 2D and 3D transient seepage analyses have been performed, using the Haaleh Dam in Iran as a case study. The results have then been compared with the values obtained via instrumentation, which reveal that 2D and 3D seepage analyses show acceptable conformity with the instrumentation results in the first few months after the start of impoundment. However, by elapsing the time needed by the dam's body and foundation materials to become saturated, 3D analysis results continue to show conformity with the instrumentation results, but the results of the 2D seepage analysis lose this concordance, and the difference between 2D analysis and instrumentation results increases.