Scale effect of rockfill materials and its influences on deformation and stress analysis of Aertashi CFRD

The influences of scale effect on the numerical analysis after construction stage of Aertashi CFRD are studied based on the super-large triaxial (800 mm in sample diameter and 160 mm in the maximum particle size) and commonly large triaxial (300 mm in sample diameter and 60 mm in the maximum particle size) test results. The test results show that the gravel and limestone blasting materials of Aertashi CFRD exhibit opposite trends on the deformation characteristics between the super-large triaxial and commonly large triaxial tests. For the Aertashi gravel materials, the parameters k and kb of Duncan-Chang E-B model for the super-large triaxial tests are 1.3~1.4 times those for the commonly large triaxial tests, while for the Aertashi limestone blasting materials, the parameters k and kb for the commonly large triaxial tests are 1.2~1.4 times those for the super-large triaxial tests. The parameters of Duncan-Chang E-B model for the common large triaxial tests fail to reflect the difference in the deformation moduli between the upstream gravel materials and downstream limestone blasting materials, which causes the simulated settlement to be inconsistent with the actual measurement. The simulated results by using the super-large triaxial parameters can well reflect the uneven settlement due to the different moduli between gravel and limestone blasting materials. The distribution and values of the settlement simulated by the super-large triaxial tests are much closer to the monitoring data. © 2021, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.