Study On Some Key Issues In Design And Construction Of Geomembrane Central Core Earth And Rockfill Dams

As a new type of impervious wall material, the geomembrane is to be used in the central core earth and rockfill dams. In this thesis, the engineering characteristics of geomembrane are mainly investigated. The reliability of impermeability, the durability, the deformation adaptability and the proper application range of geomembrane are discussed. A number of the data collected from different hydraulic engineering projects in which the geomembrane is used, and the in-situ tests and laboratory experiments are analyzed. Then the nonlinear finite element method is applied to evaluate the stresses and deformations of the selected hydraulic engineering project. The settlement of geomembrane composite central core is estimated by the rheology method. Based on the analysis and calculation results, it is proven that geomembrane is an ideally impervious material. It has good performances in such aspects as impermeability, elasto-plastic deformation adaptability, resistance ability against erosion. The life span of the proper geomembrane used in dam under water can reach over 100 years. It can be used in the earth and rockfill dams with more than 100m heights.