The Effect of Block-Matrix Interface of SRM with High Volumetric Block Proportion on Its Uniaxial Compressive Strength

The soil–rock mixture (SRM), as a heterogeneous and discrete geomaterial, can be widely found in nature and may present difficult design and construction issues for structures within or on top of them. Engineers face a difficult problem when determining the mechanical behavior of geomaterials with SRM, especially those with a high volumetric block proportion (VBP). As it is often very difficult to prepare undisturbed and representative samples of these materials. Thus, this paper proposes a novel method that can generate SRM models with a high VBP and produce a block-matrix interface (BMI) around the rock block, which can simulate unwelded SRM in nature. Then, the finite difference method (FDM) is applied to simulate uniaxial compression tests. The conformity of the numerical simulation results with the experimental results shows that the method is reasonable and effective. In addition, the effect of the strength of the BMI, the thickness of the BMI, and the geometrical shape of the rock blocks on the uniaxial compressive strength (UCS) of the SRM are also investigated. The modelling approach proposed in this paper is able to generate BMI in SRMs and enables the effect of the BMI on the SRMs’ properties to be better investigated in numerical simulations. This method can overcome the difficulties of preparing representative and undisturbed experimental cores while saving cost and improving efficiency. Simultaneously, the method proposed in this paper is promising to be extended to three dimensions.