Stress-Deformation Behavior Of High Concrete Face Rockfill Dams Built On Thick Alluvium Deposits

More and more concrete face rockfill dams (CFRD) will be built on thick alluvium deposits with the development of hydropower projects. The study on stress-deformation calculation method of high CFRD built on thick alluvium deposits has both theoretically significance and application value. The main points of this doctoral dissertation are listed as follows.1. The processing of 3D mesh of CFRD for finite element calculation is not only complicated but also time-consuming. The mesh quality has great influence on the accuracy of results of stress-deformation analysis. To solve this problem, the 3D FEM mesh of Jilintai CFRD has been intensified with the help of software TrueGrid.2. In order to transfer finite element calculation results to post- processing software Tecplot, a program is written. 3D flood mode pictures of FEM results drawn by Tecplot are concise, vividly and intuitionistic because of OpenGL technique of Tecplot.3. A 3D finite element method procedure has been written and 3D Goodman element is adopted to simulate the interface between diaphragm wall and alluvium deposits. A high CFRD - Chahanwusu CFRD has been chosen as an example to study the stress-deformation behavior of high CFRD built on thick alluvium deposits. The stress-deformation behavior and its influence factors have been obtained.4. A new idea— arc type diaphragm wall, is suggested in the article to diminish the big tensile stress distributed the zones near by the both riversides and the top zone of the concrete diaphragm wall, which usually leads to cracking of diaphragm wall and decreases the safety of diaphragm wall and dam. Comparison between the stress-strain behavior of arc type diaphragm wall and that of plane type diaphragm wall is made by using 3D finite element analysis. The calculation result shows that the tensile stress of arc type diaphragm wall is much less than that of plane type diaphragm wall although the compression stress of arc type diaphragm wall is a little larger. Since the tensile...