混凝土面板堆石坝局部止水缝失效渗透稳定分析

Seepage stability analysis of concrete faced rock-fill dam under the cases of local seal seam failure

混凝土面板堆石坝的防渗面板很容易失效,面板一旦失效对大坝的渗透速度、渗透流量以及渗透坡降产生重大影响,由于坝体工程地质条件往往比较复杂,需要研究恰当的计算方法。利用计算渗流的专业有限元软件SEEP-3D,结合工程实例,采用传统的数值计算方法,计算单一垂直缝不同位置失效的水头分布、渗透流量大小以及浸润线位置,并与解析解进行对比,结果发现渗透流量不符合渗透规律。鉴于此,在传统的数值计算方法基础上,提出一种新的数值计算方法,即在下游分别施加该失效缝位置处的水头边界,其计算结果与工程实际和解析解吻合很好。研究成果可以为混凝土面板堆石坝的防渗设计提供参考。

The impervious face of concrete faced rock-fill dam is easy to get failed.Once the impervious face fails,it can produce an important effect upon the infiltration rate,flow and slope gradient,accordingly,it is necessary to study an appropriate calculation method,for the dam body engineering geological conditions are rather complicated.The professional finite element software SEEP-3Dfor computing seepage flow-in combination with engineering real examples is used with the traditional numerical calculation method to calculate the water head distribution seepage flow dimensions and phreatic line position of the single vertical seam failure in different positions and to make the contrast with the analytical solution so that the results have found that the seepage flow is not in coincidence with the seepage laws.For this reason,based on the traditional numerical calculation method,this paper suggests a kind of numerical calculation method（i.e water head boundary should be applied to the failed seam positions downstream respectively）whose calculation results are found to be in very good coincidence with the real engineering examples and analytical solution.Accordingly,the research results can provide the references for the seepage-proof design of concrete faced rock-fill dam.