Optimization of the Clay Core of Earth Dams with Regression Method

In the optimal design of the core of earthen dams, the type of material, its dimensions and shape are very important. So that with the least volume of materials, it has the greatest effect in reducing the amount of seepage from the dam body and maintaining its stability. The purpose of this research is to develop a model for optimizing the core geometry of Hajilerchai dam near Tabriz city based on the integration of the equations obtained from the simulation of seepage, hydraulic gradient and stability reliability factor with the Simplex algorithm. In this study, two objective functions were considered, one is the volume of soil material per unit length of the dam and the other is the seepage rate from the dam body. Then, by defining 50 different sections of the core of the earth dam and using the results of numerical analysis of seepage regression relationships, stability coefficient and hydraulic gradient were obtained. In order to validate the regression relationships, the values of stability coefficient, hydraulic gradient and percolation obtained from the optimal core model were compared with the results obtained from GeoStudio software models in three sections. This comparison showed a high correlation of about 99%. The results of the model developed to determine the optimal dimensions of the earth dam core were compared with the actual dimensions of Hajilerchai dam which indicated a reduction in the volume of materials required for the construction of the dam core by about 12%, which also provides the necessary stability.