Abstract: Combining with the hydro geological conditions of the hydropower station and its layout, as well as the arrangement of seepage control system, three dimensional seepage field analysis is carried out, focusing on the performance assessment and optimization design of the seepage control system. Numerical results demonstrate that the seepage control system is properly designed and can effectively lower the phreatic surface in the surrounding rocks; the upper part of the drainage system has little effect on controlling the leakage from reservoir，therefore the space of drainage hole arrays on higher elevation can be enlarged; leakage channel exists in the existing seepage control system and can be further optimized.

Key words: underground powerhouse, drainage hole array, seepage control, seepage control system optimization

摘要： 结合水电站厂区的水文地质条件、枢纽布置、防渗体系布置等，开展了电站厂区的三维渗流场分析，评价了厂区防渗体系的有效性，并提出了优化方案。计算结果表明：厂区现有防渗体系渗控效果明显，总体合理有效；厂区上部排水系统处于计算干区，高高程排水孔幕的间距可适当加大；现有防渗体系存在渗漏通道，可进一步优化。

关键词: 地下厂房, 排水孔幕, 渗流控制, 渗控优化