糯扎渡水电站地下厂房区渗流场分析

Analysis of seepage field for underground power house of Nuozhadu Hydropower Station

联合运用固定网格的节点虚流量法及能严密地模拟排水孔实际渗流行为的排水子结构技术,对糯扎渡水电站地下厂房区渗流场进行了三维整体有限单元法分析研究.结合工程的现拟渗控设计方案经多种工况的求解,较详细地分析了该电站地下厂房区的渗流场特性,论证了现有防渗帷幕和排水设计方案的明显渗控效果,为设计提供了可靠依据.在渗流场求解方面应用了目前较好的算法:一方面把排水子结构纳入节点虚流量法中;另一方面把节点虚流量法中的渗流虚域与实域、虚单元与实单元的概念引入排水子结构,使求解有复杂排水孔幕和排水廊道的工程渗流问题得到了较好地解决.

The three-dimensional seepage field for underground power house of Nuozhadu Hydropower Station is analyzed by means of combination procedure of the fixed mesh finite element method of nodal virtual seepage flux and improved drainage substructure technique which can simulate curiously the true seepage behavior of the draining relief holes. Based on the presented seepage control design scheme, the behavior of the seepage field are analyzed in detail through calculating several possible operation conditions. The results of these models show that the seepage control of waterproof curtain and draining system is efficient; and the data can be used as the basis for design. In a word the authors have used the best method at present for solving the seepage field. Based on the numerical method of nodal point virtual flow rate with a fixed mesh which can solve free surface, the authors present the drainage substructure technique which is suitable to solve engineering seepage field problem with complex drainage-hole curtains and drainage galleries.