Laboratory-Scale Investigation on Shear Behavior of Non-Persistent Joints and Joint Infill Using Lattice-Spring-Based Synthetic Rock Mass Model

Abstract

Discontinuities mainly control the mechanical behavior of rock mass and cause a significant reduction in the rock mass strength. Joint persistency and joint infill conditions are considered the most significant joint parameters that control the mechanical response of rock mass. In this study, numerical and statistical analyses were performed on pre-cracked specimens with two flaws to investigate the effect of joint persistence parameters on shear strength. In addition, an extensive study was conducted to explore the effect of infilled mineral strength, infill thickness, and infill wall roughness on shear strength. The Lattice-Spring-Based Synthetic Rock Mass (LS-SRM) approach was utilized to perform the numerical models. The results showed that the tensile crack propagation is limited at higher normal stresses as tensile damage is largely suppressed. The increases in rock bridge angle slightly increased the shear strength and caused a change in the failure mechanisms of the rock bridge from tensile to shearing. The results of the models with infilled minerals revealed that infilled minerals mainly controlled the shear strength of specimens when the infill thickness was 4.0 mm or greater. The infill wall roughness had no apparent effect on the shear strength. In contrast, it governed the failure mechanisms; cracks initiated at the asperity of the rough filling wall and propagated through the hosted rock mass.

Numerical Investigation for the Effect of Joint Persistence on Rock Slope Stability Using a Lattice Spring-Based Synthetic Rock Mass Model

“…A trial-and-error approach, as presented in the flowchart in Figure 8, can be ar duous and time-consuming. In an effort to make this process more efficient, the presen study employs an approach by utilizing the equations proposed by Al-E'Bayat et al [41] These equations have been demonstrated to provide estimations of micro parameters with an error margin of less than 10%, ensuring that the simulated values closely align with th experimental data while significantly reducing the challenges associated with the trial and-error methodology. Using established equations contributes to our numerical simu lation efficiency and the precision of the micro-mechanical property input process.…”