Safety Evaluation of Seepage Behavior for Zhangkeng Reservoir Dam

The Zhangkeng Reservoir is an earth dam with height of 26m, which has been reinforced for several times during the running period of about 50 years. Based on the field safety check and analysis of seepage observation data, the seepage field of the dam is inversed under the running water level by the finite element method (FEM), and the comprehensive seepage parameter of the dam material is obtained. By use of the finite element model adjusted by back analysis, the seepage fields under the normal water level, design flood water level and check flood water level are obtained by the steady seepage theory, and the distribution of piezometric head and penetration gradient of dam and its foundation are analyzed. It is shown that the maximum penetration gradient of dam body and its foundation are larger than their allowable penetration gradient. It is suggested that the anti-seepage system of the dam be reinforced for improving the seepage behavior of the dam.