关键词: 胶凝砂砾石(CSG); 力学性能; 硅灰; 单轴压缩试验; 本构模型;

Abstract: Cemented sand gravel(CSG)is a new type of dam construction material with low strength and low elastic modulus.In order to improve the mechanical properties of CSG materials, natural gravel was selected as the raw material, and six batches of specimens were prepared with different dosages of silica fume(0,2 %,5 %,8 %,10 %,12 %)instead of cement.The influence of silica fume content on the mechanical properties of CSG materials was studied by uniaxial compression test of CSG specimens.The results showed that the silica fume content had a significant effect on the macroscopic stress-strain behavior of CSG.With the increasing of silica fume content, the compressive strength and elastic modulus increased, and the peak strain decreased first and then increased.By establishing the constitutive model considering the content of silica fume, the variation law of five characteristic parameters in the statistical damage model was analyzed, and the expression of five parameters with the content of silica fume was obtained by fitting, and then the influence of silica fume content on the damage evolution mechanism of cemented sand gravel was studied.

Key words: cemented sand gravel; mechanical property; silica fume; uniaxial compression test; constitutive model;