伪随机流场法在堤坝渗漏探测中的应用与研究

伪随机流场法具有快捷、直接、精确有效等优点,逐步成为堤坝渗漏探测的主流方法。利用该方法,在漏水区域、库区无穷远段进行高压供电,库区内网格状布置测点,可查找渗漏入水点。通过对各异常区域的区域面积、异常区域内各测点的异常平均值以及对于严重渗漏的临界值进行计算,可判断水库渗漏通道和各渗漏点的渗漏量比例。此外,由于该方法快速便捷的特点,可以运用该方法进行实时监测。应用于某混凝土面板堆石坝的探测结果表明,利用堤坝周边已经存在的监测孔或在灌浆帷幕下游进行钻孔,进行伪随机电位差或者电流测试,可在无损条件下判断渗漏来源和通道发育方向,检测防渗处理效果。该方法可为堤坝渗漏监测预警、拟定防渗处理方案提供依据。

Study and application of pseudorandom flow-field method for detecting seepage of dyke and dam

As pseudorandom flow-field method has the merits of quickness， directness， accuracy， etc.， it gradually becomes the main method for detecting seepage of dyke and dam. With this method， the seepage-inflow point can be detected by supplying high-voltage electric power to the seepage area and reservoir area with infinite distance and arranging detecting point with grid pattern in reservoir area. Through the calculations made on the areas of all the abnormal regions and the abnormal average values of all the detecting points in the abnormal regions as well as the critical values of serious seepages， the seepage passages in reservoir and the proportions of seepage amounts of all the seepage points can be estimated. Moreover， as the method has the performance of quick detection， it can be applied to the relevant real-time monitoring. The detection result from the application of the method to a concrete face rockfill dam indicates that if making pseudorandom potential difference testing or current testing on the existing monitoring holes around dyke and dam or the holes drilled in the downstream zone of grouting curtain， the seepage source and the developing direction of the seepage passage can be judged under a non-destructive condition， so as to test the effect of anti-seepage treatment. This method can provide a basis for the monitoring and early-warning of the seepage of dyke and dam and making the relevant anti-seepage treatment scheme.