江河大堤均匀砂基渗透破坏机理试验研究

为了摸清大堤堤基出现渗透破坏甚至溃决的原因,专门进行了模型试验。根据对堤基地质及水文地质的分析,将复杂的堤基归纳并概化为三种类型,并分别进行了各类模拟试验。阐述了均匀砂层堤基的渗透破坏特性及影响因素。均匀砂基的渗透破坏主要发生在堤基上部,特别是大堤与堤基的接触带,破坏水力比降决定于砂层土料本身的破坏水力比降,当大堤与堤基之间存在脱开问题,则破坏水力比降为砂层表面的冲刷水力比降。

Failure mechanism of seepage in uniform sand foundation of river levee

Based on the analysis of the geology of levee foundation and hydrologic geology,in order to understand the reason of seepage failure occurred in the levee foundation,the complex levee foundation was divided into three kinds,and the simulation experiments were performed.The failure characteristics and influencing factors of seepage were studied for uniform sand foundation in laboratory.It was found that seepage filure of uniform sand foundation mainly occurred in the contact zone of levee and levee foundation,and the failure hydraulic gradient was dependent on the failure hydraulic gradient of sand seam.When there was declutch problem,the failure hydraulic gradient became the washing hydraulic gradient on surface of sand seam.