Numerical simulation of a layered rock under triaxial compression

Layered rock masses are common geological materials. Their traverse isotropy greatly affects the stress-strain analysis of rock masses and fracture mechanical behaviors [1]. Many scholars have conducted theoretical and experimental studies on the mechanical properties of layered rock masses. Aimed at exploring a jointed rock mass under failure by sliding along joint planes, the earliest study was initiated by Jaeger [2], who established the layered rock mass strength description model based on the Mohr-Coulomb criterion. Thereafter, some scholars added supplements and made improvements to this model [3-11]. Some other scholars conducted research on layered rock masses from the perspective of their nonlinear mechanical behaviors. For example, Duveau and Shao [12] adopted the combined nonlinear failure criterion to describe the failure characteristics of layered rock masses. Tien and Kuo [13] used two different materials to facilitate an artificial prefabrication of three groups of layered rock masses of different inclinations. The effect of the layer inclination on the overall strength and elastic modulus of rocks was studied, and corresponding failure criteria in terms of the two varying models of layered rock failure were established. Cazacu et al. [14] took hydrostatic pressure into account and included the strength criterion expressed by invariant stress based on the quadratic equation failure criterion. All these scholars mainly, used the uniaxial compression test or the conventional triaxial compression test in their studies. However, research on the response characteristics of layered rock masses in true triaxial compression is limited; Lee and Pietruszczak [11] proposed a formulation describing the strength anisotropy of transversely isotropic rock masses, and used true triaxial compression tests as well as conventional triaxial tests for verification. For further study, the present article uses numerical simulation method to examine the strength and deformation characteristics of layered rock masses under conventional and true triaxial compressions. The aim is to provide reference to forecast the behavioral characteristics of real samples.