Abstract: The preparation of model materials plays a crucial role in structural model test. To investigate the impact of various factors on the physical and mechanical properties of model materials, we employed orthogonal test to design the material proportions, and obtained the mechanical parameters of the model materials using a triaxial test apparatus. By conducting sensitivity analysis on the physical and mechanical properties of the model materials, we determined the influences of factors such as the aggregate-binder ratio, cement-gypsum ratio, sand-barite powder ratio, refined iron powder amount, and sand particle size. Based on the sensitivity analysis, we obtained a preparation method for hydraulic structure model materials. Taking a cementitious sand gravel (CSG) dam as a prototype, we created a structural model of the CSG dam using the aforementioned material preparation method and conducted failure test on the model using overload method. The obtained failure model, which involves sliding of the dam body along penetrative cracks along the foundation surface, is compared with finite element results. This model better simulates the actual failure of the CSG dam, demonstrating the reliability of our findings: physical and mechanical parameters of model materials are affected by material proportion factors.

Key words: similar materials, orthogonal test, triaxial shear test, sensitivity analysis, model of cementitious sand gravel dam