Based on the test results and the regression equations, a method for selecting appropriate similar materials to simulate rocks was proposed. A Python script for implementation was developed. A...

Sandy gravel stratum is very common in tunnels and underground engineering projects. The accurate determination of mechanical parameters is crucial for engineering design and construction. The Hardening Soil (HS) Model, which accounts for both shear hardening and compression hardening, has demonstrated advantages in numerical simulations. This study conducts large-scale mechanical experiments, including triaxial drained shear tests, loading-unloading tests, and standard consolidation tests, on sandy gravel specimens. The results reveal that the ratio of the three stiffness parameters in the HS Model, namely Young’s modulus under triaxial loading (E₅₀), oedometric loading (E_oed), and unloading-reloading (E_ur) is 1:1:4.3. The validity of the established stiffness ratio relationship is verified through numerical simulations of a foundation pit project and comparison with field monitoring data, demonstrating a consistent agreement between the simulation results and actual monitoring values.

The cement‐plaster bonded rock‐like material is one of the most commonly used materials to simulate different rocks in physical model tests. However, the applicability of this material in solid‐fluid coupling model tests is not clear because there are few research studies on the water‐physical properties of this material and its similarity to the actual rock is uncertain. This paper presents a systemic experimental study on the water‐physical properties of the cement‐plaster bonded rock‐like materials. The parameters of rock‐like materials, including water absorption, softening coefficient, and permeability coefficient, were compared with those of actual rocks to analyse the applicability of such material. Then, the influence of proportion on the water‐physical properties of this material was discussed. By multiple regression analysis of the test results, empirical equations between the water‐physical parameters and proportions were proposed. The equations can be used to estimate the water‐physical properties of cement‐plaster bonded rock‐like materials with specific proportion and thus to select suitable materials in the solid‐fluid coupling physical model tests.