前言闸坝下游渗流出逸处,最易发生渗透破坏,诸如流土、管涌等,有时在设置反滤层后,也常常会淤堵,最后仍将导致失事。造成渗透变形的原因是渗流出逸坡降大于该处土料的临界坡降或允许坡降,因此设计人员必须严格控制渗流出逸坡降。鉴于目前国内外对渗流出逸坡降还没有专门的全面系统的讨论,现有的计算公式仅适用于较简单的地下轮廓,而对于一些复杂的地下轮廓布置,还没有现成的计算方法可供采用。此外,常有这种看法,认为延长渗径长度就可以减小渗流出逸坡降,其实这种观点并不完全正确,需视具体工程布置情况而定。为此,本文拟对这些问题作一初步探讨。 Preface The seepage downstream of the sluice dam is prone to infiltration and destruction, such as earthflowing and piping. Sometimes it is often clogged after the anti-filtration layer is installed, which will eventually lead to crashes. The reason for the infiltration deformation is that seepage flow out of the slope is greater than the critical gradient of the soil material or allowed to decline, so the designer must strictly control the flow out of the escaped slope. In view of the fact that there is no comprehensive and systematic discussion about the desorption of seepage at home and abroad at present, the existing calculation formulas are only applicable to simpler underground profiles. For some complex underground contouring arrangements, there are no available calculation methods available use. In addition, this view often holds the view that extending the length of the seepage path can reduce the seepage and descending flow of seepage. In fact, this view is not entirely correct and depends on the specific project layout. To this end, this paper intends to make a preliminary discussion of these issues.