Seepage Analysis of Earth Dam with Anisotropic Material Permeability

Seepage analysis of earth dam is the important basis for the evaluation of seepage safety and scheme design of seepage control.According to the vibration filling construction characteristics of the earth dam of Dalong water-control project in the middle and lower reaches of Ningyuan River in Sanya city of Hainan Province,the seepage fields of earth dam under different working conditions were analyzed based on the three-dimensional saturated-unsaturated seepage theory.The seepage fields based on the anisotropic and isotropic material permeability were compared and the results showed that(1)as for the earth dam under vibration compaction without foundation pit,layered compaction can cause the anisotropic material permeability,which can have greater impacts on the anti-seepage earth material with lower permeability and result in the phenomenon of increasing seepage velocity in the anti-seepage material upstream of earth dam and decreasing seepage velocity in the anti-seepage material in the middle stream of earth dam;(2)anisotropic material permeability can lower the seepage discharge significantly across the entire section of earth dam;and(3)distribution of pore water pressure in the earth dam is closely related to the upstream water level,and the seepage velocity and seepage discharge in the earth dam is affected by the difference of upstream and downstream water levels.