为研究白鹤滩水电站层间错动带渗流特性,以电站右岸层间错动带C3为研究对象,基于FEFLOW建立了承压二维非稳定流有限元渗流模型,模拟在正常蓄水位825 m时,分析不同防渗帷幕布设下地下水渗流场分布及对右岸地下厂房区的稳定性影响.结果表明,帷幕和错动带渗透性对渗控效果影响明显,降低帷幕渗透性能显著减少排水廊道的排水量及降低厂房区的自由面高度;在现有帷幕布设下,帷幕渗透系数为1.0×10-5cm/s时,厂房区上游的最大水力坡度值为9.25,超过了临界水力坡度值,而全封闭式帷幕布设能取得较好的渗控效果;与封孔情况相比,坝区勘探孔未封闭使厂房区上游最大水力坡度明显增大,且排水廊道排水量增加1.3倍,故在坝肩采用全封闭式帷幕且封闭勘探孔,能够有效降低厂房区的水头,为白鹤滩水电站防渗排水系统设计提供重要的科学依据.%In order to study the permeability of interlayer staggered zone,the interlayer staggered zone C3of Baihetan Hydropower Station is taken as a example.A two-dimensional transient flow in the confined aquifer of finite element numerical simulation model based on FEFLOW was built for analyzing the distribution of groundwater seepage field with different grouting curtain and its influence on the underground plants of right bank when the normal storage level is 825 m. The results indicated that the effect of curtain and interlayer staggered zone permeability on the seepage control is obvious,reducing curtain permeability can markedly lessen tonnage of drainage corridor and lower the free height of underground powerhouse caverns.Under the current curtain setting,when curtain permeability is 1.0×10-5cm/s,the maximum hydraulic gradient value of underground powerhouse caverns upstream is 9.25 surpassing the critical hydraulic gradient value but the totally enclosed curtain setting can obtain better seepage control effects. Compared with the sealing holes,the unsealed exploration hole in the dam area significantly increases maximum hydraulic gradient value in upper reaches of the workshop and the tonnage of drainage corridor increases 1.3 times too. The assessment results showed that combination with the totally enclosed curtain and closed exploration hole can effectively reduce the head of workshop area and basically meet the design requirement of seepage control.The findings can provide important scientific basis for the design of anti-seepage drainage system at Baihetan Hydropower Station.
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