Abstract: Doyraj dam is a zoned embankment dam with a height of 65 m, laid on a relatively permeable formation. The selected type of foundation water tightening system is a cutoff wall. In order to make a reliable estimation of the foundation permeability coefficient in- situ permeability tests has been performed in conjunction with 3D seepage back analysis. Three different ratios of horizontal to vertical permeability coefficients have been considered in the calculations. The evaluated in-situ permeability coefficient of the foundation has been used in other 3D seepage analyses to study the effect of the extension length of the cutoff wall into the abutment on the amount of seepage.

Key words: permeability coefficient, evaluation, water tightening system, 3D seepage back analysis

摘要： Doyraj 大坝是分区土石坝，坝高65 m，坝基为相对透水构造。选择截渗墙作为坝基防渗系统。为可靠估算坝基渗透系数，进行了现场渗透测试和3D渗透反分析。计算中考虑3个水平渗透系数和垂直渗透系数的比值。估算的坝基现场渗透系数还被应用于其他3D渗透分析中，以研究截渗墙延伸进坝肩长度对渗透量的影响情况。

关键词: 渗透系数, 评估, 防水系统, 3D渗透反分析