WORKABILITY OF THE ZIGZAG POLYMER DIAPHRAGM OF HIGH EARTHFILL COFFERDAM
Pages 490-495
There are considered the results of stress-strain state analysis of polymer diaphragm in the body of the 50 m high earthfill cofferdam of Gibe III dam. The diaphragm is made of polyvinylchloride (PVC) geomembrane and has a zigzag location. Computations were conducted with the finite element method. A thin geomembrane was modeled by rod-shaped finite elements. Computations showed that the diaphragm made of geomembrane is a sufficiently safe seepage-control element: there are small tensile stresses on its individual sections. The geomembrane damage may occur in it only in the part anchored to the upstream shell. Considerable tensile stresses appear in anchors which are comparable with the geomembrane tensile strength. If the geomembrane is made of PVC, there will be a margin of safety. It is not recommended to anchor the diaphragm into the upstream shell but make it only into the downstream shell.
DOI: 10.22227/1997-0935.2017.5.490-495