Evaluation of Grout Curtain Performance in Seepage Control from Rock Formations by 3D Analysis(A Case Study of Haigher RCC Dam)

The issue of water seepage from foundations and abutments is one of the main challenges related to the design and construction of dams. One of the most important parameters in dam design in the study of seepage is to determine the permeability of the dam site, especially in rock formations. In this study, first, the permeability of Haigher roller compacted concrete dam site, located in Fars province, was determined through extensive Lugeon tests before and after the grout curtain. Then, using PLAXIS 3D FEM software, the site topography was modeled in three dimensions and three-dimensional dam seepage analysis was performed. The efficiency of the grout curtain was evaluated using numerical analysis. The results show that the total seepage discharge in the Haigher dam construction site without grout curtain is 1.075 * 10-2 and after the construction of the grout curtain is reduced to 2.305 * 10-3 m3/s, which indicates a reduction of about 80% seepage discharge due to construction of grout curtain. The results of the parametric study showed that with increasing the depth of the grout curtain, the seepage flow decreases and with increasing the upstream water level, the seepage flow rate from the dam increases linearly.