Abstract: Based on the monitoring data by piezometers at Zoumazhuang auxiliary dam of Miyun Reservoir from 2015 to 2021, combined with analysis of seepage gradient, contour of water table, piezometric levels under specific reservoir levels and saturation lines on cross section as well as regression analysis, it is concluded that the Zoumazhuang auxiliary dam is safe and stable. In consideration of the defects in dam section Ⅲ and section Ⅳ, monitoring and data analysis should be strengthened in operation.

Key words: South-to-North water diversion, Miyun reservoir, Zoumazhuang auxiliary dam, seepage , analysis

摘要： 选取密云水库走马庄副坝2015—2021年测压管监测资料，通过渗流梯度分析、等水位线分析、特定库水位下的测压管水位对比分析、横断面浸润线分析和回归分析，得出密云水库走马庄副坝渗透总体稳定，大坝运行总体安全。但Ⅲ号和Ⅳ号坝局部存在防渗缺陷，运行中需加强观测与分析。

关键词: 南水北调, 密云水库, 走马庄副坝, 渗流分析