Experimental and numerical investigation on uniaxial compression test of layered slate

In order to investigate the effect of bedding structure on the mechanical properties of rock masses, the layered carbonaceous slate of the Muzhailing Tunnel in Shaanxi was taken as the research object, and experimental and numerical analysis were conducted on the mechanical properties of the layered slate in the uniaxial compression test. The discrete element framework MUSEN, which is also called bonded particle model (BPM), was used to simulate the failure behavior of layered rock mass in the quasi-static compression process. The results show that: 1) The microscopic elastic modulus and the macroscopic elastic modulus are roughly linear. Through interpolation calculation, the elastic modulus of the test can be mapped to the microscopic modulus for numerical simulation calculation. 2) As the axial and tangential stiffness increases, the load and displacement corresponding to the peak value increase. 3) Under the same parameters and boundary conditions, according to the principle of randomness, a variety of different particle distribution models are formed. The final load-displacement curve shows that the model has little effect on its mechanical response. 4) In the test, when the bedding angle is 0° and 90°, the peak load is larger; when the bedding angle is 30°, 45° and 60°, the peak load is closer, which means that with the gradual increase of the inclination angle, it is roughly U-shaped distributed. 5) In terms of failure morphology, splitting tensile failure, shear-slip failure and composite tensile-shear failure are generally present at different bedding inclination angles. The failure modes can be summarized as straight, broken and curved failure. 6) With the same model, different bedding models are constructed through programming. The mechanical response of the simulation results and the comparison test of the failure form have good consistency, and the split evolution of the layered slate at different bedding angles is reproduced. © 2022 Central South University of Technology. All rights reserved.