Sensitivity Analysis of Key Mechanical Parameters in the Uniaxial Compressive Strength Test Using Numerical Simulation

Abstract

Predicting the mechanical behavior of rocks under loading is crucial for stability analyses and the design of underground and mining structures. A primary challenge lies in identifying and quantifying the influence of Geomechanical parameters on ultimate strength and failure mechanisms. In this study, a parametric sensitivity analysis was conducted to assess the effects of four key parameters—loading rate, friction angle, cohesion, and Young's modulus—on rock behavior under compressive loading. Numerical simulations were performed by varying each parameter independently while keeping the others constant. Results indicate that increasing the loading rate enhances the peak strength. The ultimate strength is primarily governed by cohesion and the friction angle, whereas Young's modulus affects only stiffness and the slope of the elastic portion of the stress–strain curve, without influencing peak strength. All specimens exhibited post-peak softening, with failure characterized by progressive development of shear zones and fracture surfaces. Cohesion was found to exert a more substantial influence on ultimate strength than the friction angle.