Meticulous simulation and evaluation of seepage control effects at right bank dam foundation and underground powerhouse of Jinping I hydropower station

Abstract

This case study presents a systematic performance assessment of the seepage control system at the right bank abutment of Jinping I Hydropower Station. By utilizing the in-situ measurements of seepage field, the characteristics of groundwater flow behaviors in the dam foundation and around the underground powerhouse were analyzed. Based on an equivalent continuum method, an anisotropic seepage tensor model of the fractured rock mass in the dam site area was established. Considering the features of topography, geological settings and hydraulic structures, a three-dimensional finite element mesh with complex seepage control structures was generated. A numerical method combining a substructure technique, a variational inequality formulation of Signorini’s type and an adaptive penalized Heaviside function (short for SVA method) is adopted to simulate the three-dimensional seepage field at the dam site. On this basis, the distribution of seepage field during the operation period was predicted, and the performance of the seepage control system was evaluated. Besides, the influence of critically oriented fractures along the direction of NWW on the seepage control effect was also discussed. The methodology presented in this study is useful for understanding the groundwater flow behavior and the performance of the seepage control system in hydraulic engineering.