Abstract: In the underground engineerings of waterpower, petroleum and traffic, the problem of seepage often happens. If it is not deal with correctly, worse stress will be induced, which willinfluence the stability of structure. Based on the model of unsaturated seepage, the analysis of unsteady seepage is accomplished.
In this paper, according to the construction by stages, under the continuity premise of seepages variance, the guasi-steady seepage for every stages is analyzed and accordingly a numerical model of three-dimensional unsaturated seepage is constituted. Based on the principle of water quantity balance the excavation is simulated with the model of substructure; the waterproof curtain with the model of interlayer; the drainge with the model of shank element.
According the above models a finite element program of unsaturated and unsteady seepage analysis is compiled using finite differnce method and the dynamical simulating of seepage field in complex region is done. The crnalysis and calculation of engineering case show that the results obtained by calculation of above models are reasonable.