| The changes of reservoir water level will result in the changes of groundwater level in the reservoir area, which make significant impact on bank slopes, buildings, farms, living environment and ecology. In this thesis,3D saturated-unsaturated and steady-unsteady seepage model are established by three dimensional finite element method for simulating the groundwater flow in the reservoir area and assessing the effect of reservoir water level changes on groundwater dynamic characteristics. Main content of the thesis as follows:(1)Galerkin weighted residual method is used to solve the seepage mathematical model, three-dimensional finite element scheme with eight-node isoparametric elements for unsteady seepage is derived. The treatment of a variety of boundary conditions are discussed, especially free surface boundary and the calculation of integration term for unsteady seepage free surface.(2) The finite element programs for three-dimensional steady-saturated and unsteady-saturated seepage model are developed by Fortran. Compressed sparse row format(CSR) and SSOR-PCG are adopted to solve the linear algebraic equations. The programs have been verified respectively by analytical result of homogeneous dam and test data of sand box.(3) The groundwater dynamic characteristics of the important sections of Xiaonanhai reservoir are studied by saturated-unsaturated seepage model. The groundwater flow of Luohuang, Huapu, Degan section are separately simulated before and after water storage of reservoir, and during the flood period. It’s shown that the gradient of groundwater movement, groundwater depth, the change range of water level all have a certain degree of variation.(4) According to the simulation results of groundwater flow of three typical reservoir sections, the effect of bank topography, formation permeable structure, and other factors on groundwater of reservoir area have been analyzed. Research results provided scientific base for engineering decision and design. |
PDF Full Text Request