Advanced hydromechanical modeling of andesitic and granodiorite massifs applying the Hoek-Brown criterion for the stability of underground excavations

Abstract

The study focuses on the advanced hydromechanical modeling of andesitic and granodioritic rock masses applying the Hoek-Brown criterion to evaluate the stability of underground excavations in the Phase2 software of Rocscience. The interactions between the pore pressure, the rock deformation, and the stress variations were analyzed under dry conditions, with a water table located at the contact between both rock masses, and seismic alterations using horizontal and vertical coefficients. The results demonstrate that the increase in the pore pressure reduces the effective strength of the rock mass, and this compromises the stability of the excavations. Under seismic conditions, the redistribution of stresses and the alteration of the stress state increase the susceptibility to deformation. These findings highlight the importance of incorporating efficient drainage and adaptive support systems to ensure the stability. In addition, the study highlights the need for an integrated geotechnical approach in the design of underground excavations.