Research on the control effects of groundwater immersion on the left reservoir bank of Xingan Navigation and Power Junction in Ganjiang River

It is of great significance to study the seepage control measures of the dual structure reservoir bank for the management of groundwater resources and the layout of flood control projects in disaster areas. Taking the left bank of the Xingan Navigation and Power Junction on the Xingan section of the Ganjiang River as the research object, and on the basis of the regional groundwater flow dynamic numerical simulation technology, this study establishes a finite element seepage model of 3D unsteady groundwater flow, and a comparative study was made on the dynamic evaluation of groundwater infiltration in the reservoir area after storage and the effects of the combined measures of infiltration control (impervious wall, relief well and farmland -raised engineering). The research results show that, in the case of no seepage wall, serious seepage infiltration occurs in the area along the river on the left bank of the reservoir and the coastal low -lying areas within three years of reservoir storage. However, by jointly deploying the seepage prevention wall, the relief well, and the lifting project control measures, the immersion range can be effectively controlled within the levee project, and under the effect of impervious wall, the drainage level of the relief well is the most sensitive parameter for immersion control. Recommended layout parameters for control engineering include: the hydraulic conductivity of the impervious wall is set as 17.28×10-3 m/d, the well spacing is 30 m, the drainage water level of the relief well is 29 m, the distance between the relief well and impervious wall is 30 m. The results of this research can also provide scientific basis for the arrangement of seepage control schemes in the early stage of the project.