万家口子水电站拱坝坝基三维渗流场分析及渗控措施研究

运用Visual Modflow软件对万家口子水电站拱坝坝基渗流进行了模拟研究,用六面体单元精确模拟了排水孔孔径、孔深和孔距及帷幕的空间分布,同时对影响渗流场主要的渗流通道,如不整合面、断层、裂隙带等进行了精确模拟,在此基础上分析了坝基渗流场分布规律。综合评估了坝基渗流场的主要渗流特性、宏观渗流控制能力和局部渗流控制薄弱环节。研究表明,不整合面对坝基渗流特性影响很大,建议施工时应尽量开挖到不整合面以下,或将帷幕穿透不整合面以提高帷幕的防渗效果。

Three-dimensional seepage analysis of Wanjiakouzi Arch Dam foundation and countermeasures for seepage control

Three-dimensional seepage analysis of the Wanjiakouzi Arch Dam is conducted using commercial Visual Modflow software.The depth,diameter and distance of the drainage holes as well as the spatial distribution of the impervious curtain was simulated using hexahedron element.Main seepage paths are also simulated that include unconformable surfaces,faults and joints. Based on the analyses,Several aspects are comprehensively evaluated including seepage characteristics,large-scale seepage control capability and the weakness in local seepage control.The studies show that the unconformable strata have severe impacts on the seepage characteristics of dam foundation.Therefore it is suggested that excavation should extend to the elevations below the unconformable surfaces.In addition,it is also suggested that impervious curtain should penetrate the unconformable strata to improve its seepage control effects.