Study On Rheology Model Of Rockfill Materials And Its Application In Concrete Face Rockfill Dam

Rheology deformation is one basic engineering characteristics of rockfill materials. As present, studies related to this area in Concrete Face Rock-fill Dam (CFRD) are very few. With the development of high CFRD, more attention is being paid to the rheology deformation of the dam body. In this thesis, the calculation method of three dimensional finite element was applied to analyze the Shuibuya CFRD and the rheology deformation of CFRD is investigated based on the improved three parameters rheology model.The main contribution includes:(1) The rockfill constitutive model which used to analyze the stress-strain of CFRD frequently is appraised. In order to rationally predicting the stress-strain behavior of CFRD, The Duncan E-B model and the Elliptic-Parabolic Yield surface model are used to calculating and studying the Shuibuya CFRD. The calculated results are indicated that the two results are less than actual for not considering the the rheological characteristic of rockfill. In a word, the Elliptic-Parabolic Yield surface model can reflect the stress deformation characteristic reasonably.(2) On the foundation of the correlated experiment information and considering the rheological characteristic of rockfill, a new rheology model is proposed by improving the three parameters rheology model, and the dependability of the model is validated by using the experience formula of hyperbola function.(3) The thesis has done sensitivity analysis based on three dimensional finite element method. By choosing the representative survey points in observational information of Shuibuya CFRD, three high-sensitivity parameters of the Elliptic-Parabolic Yield surface model and parameters of rheology model are done with back analysis.(4) According to the parameters obtained from back analysis, three dimensional finite element analysis is conducted on the stress and deformationthe of the CFRD ,including their distribution and pattern with and without rheological calculated. The deformation characteristics of CFRD in the state of the improved rheology model and the original three parameters rheology model are analyzed. The results are indicated that rheology of rockfill has a significant influence on the stress and strain of dam and the improved rheology model can reflect the rheological characteristic of rockfill reasonably.