地下厂区渗流场参数反演分析及帷幕布置方案研究

Study on inversion analysis of permeability coefficient and layout scheme of curtain in area of underground plant

现代水电站建设中,地下厂区规模日趋宏大。由于地下厂区多位于降雨形成的天然水位线以下,渗漏成为主要问题。针对某工程复杂的地质条件和防渗措施,建立厂房区及坝区的三维整体模型,采用三维有限元法对稳定渗流场进行计算。运用反问题正算的方法反演枢纽区天然渗流场,在此基础上,对两种不同帷幕布置方案下厂区渗流场、渗流量以及坡降等水力要素进行对比分析。分析表明:枢纽区天然水位较高,防渗帷幕和排水孔幕组成的渗控系统对厂房区地下水位具有较好的控制作用;厂前封闭式帷幕相对于开敞式帷幕的渗控效果更加明显,结合渗流控制效果和工程造价的角度,优先推荐采用封闭式帷幕进行厂区渗流控制。

In construction of modern hydropower station , the scale of underground powerhouse is increas-ingly expanding .Because the area is mostly located below the natural water level which is formed by rain-fall, so the area faces with the problem of leakage .Aimd at the complex geological condition and seepage control measures,the paper established 3D finite element model in the areas of powerhouse and dam ,and took 3D finite element method to calculate the stable seepage field .The permeability coefficients are de-termined by the back analysis of finite element model based on boring date .Based on the back analysis , the seepage field characteristics of the underground powerhouse cavers are analyzed and the seepage con -trol effects of two kinds of seepage control schemes are compared .The results show that the hub area with high natural water level and the seepage control measures can obtain good seepage control effect .The closed curtain can obtain better seepage control effect compared with opened curtain .The closed curtain would be the priority to control the powerhouse seepage field from the perspective of seepage control effect and project cost effectiveness .