白鹤滩水电站地下厂区防渗排水系统设计

Design of seepage control system for the underground powerhouse of Baihetan hydropower sta⁃tion

白鹤滩水电站左右岸地下厂房均采用首部开发方式,位于坝肩上游左右岸山体内,距离上游水库较近。根据厂坝区水文地质条件,参照类似工程防渗排水系统的设计经验,综合考虑白鹤滩水电站的规模和重要性,提出了白鹤滩水电站地下厂区防渗排水系统的设计原则,并拟定不同的防渗排水布置方案,利用三维渗流有限元法计算分析了地下厂区渗流场和渗流量,从而确定了合理经济的防渗排水方案。研究结果表明,设计方案能够显著降低厂区地下水位及渗透压力,提高洞室围岩的稳定性。

The underground powerhouses on the left and right bank of Baihetan hydropower station are all developed from head,which are located in the mountains upstream of dam abutment and close to the upstream reservoir.Based on the hydrogeological conditions,the design experience of similar projects,and comprehensive consideration of the scale and importance of Baihetan hydropower station,the design principle of seepage control system for the underground powerhouse is determined and different seepage control plans are proposed.The seepage field and seepage flow rate are calculated and analyzed by the three-dimensional seepage finite element method,so as to determine a reasonable and economic seep⁃age control system.The research results show that the design scheme can significantly reduce the groundwater level and seepage pressure around the powerhouse and improve the stability of the sur⁃rounding rock of tunnels.