堤防渗流计算的基本方法与渗流控制措施

关于堤防中的渗流问题,中国和荷兰两国对堤防渗透破坏模式和管涌机理的分析方法不同,但本质上是一致的.荷兰学者的研究主要集中在作用于结构上的水头与管涌侵蚀长度之间的关系,而中国学者的研究则主要集中于渗透破坏模式和土颗粒组成之间的相互关系.对于水头与渗径关系的确定,Sellmeijer公式较传统的Bligh和Lane经验公式具有更好的适用性.在渗透稳定分析中,有限元渗流计算结果应结合渗流比降与土体抗渗特性之间的关系进行分析.对于堤防的渗流控制,应采取上游防渗铺盖、下游盖重、反滤层、减压井等综合措施.

Methods of seepage analysis of river dikes and seepage control measures

For dealing with seepage problems in river dikes,the methods for analyzing seepage failure modes and piping mechanism adopted in China and the Netherlands are different.But their key points are essentially the same.The research works of Dutch scholars mainly focus on the relationship between the water head acting on structure and the piping erosion length.While Chinese scholars mainly pay attention to the relationship of seepage failure mode with the soil grain composition.To determine the relation of water head with seepage length,the Sellmeijer formula is more applicable than the traditional Bligh and Lane formula.When applying FEM seepage analysis,computation results should be combined with analysis of the seepage gradient and the anti-seepage properties of the soil.For seepage control of river dikes,comprehensive should be considered application of upstream blanket,downstream berm,filter layer and relief well,etc.