Abstract: The materials of most barrier dams comprise soil-aggregate mixture featured with a wide range of grading, and its rheological deformation is crucial to the long-term safe dam operation. This study conducts a consolidation-rheology test of three typical mixture materials with wide grading, using a large-scale testing apparatus. Analysis on the test results reveals that rheological strain increases with vertical stress following a logarithmic law, and the trend of increase is more prominent in the case of high vertical stress. We have examined the effect of material grading characteristics on rheological deformation, finding relatively small deformation in well-graded materials with large non-uniformity coefficients, while more significant deformation in materials with low grading characteristic values and high contents of fine particles. A four-parameter hyperbolic rheological model is constructed for time variations in the deformation; and it proves quite accurate as shown in our test results, well reflecting the consolidation-rheology characteristics of soil-aggregate mixture materials with wide grading.

Key words: soil-aggregate mixture material, wide grading, consolidate-rheology test, rheological model