Study on strength parameters of rock mass with stochastic combination discontinuities and their application in a tunnel in China

摘要

The rock mass has special properties, such as inhomogeneity, anisotropy, discontinuity, and nonelastic, due to variousinternal or external stress in the process of its formation. In this study, similar materials are considered to simulate therock mass and analyze the failure law using laboratory tri-axial tests based on the similarity principle. The rock mass anddiscontinuity are constituted in the process of model construction by considering the influence of the orientation, spacing, and number of discontinuity, respectively. Then, the influences of the orientation, spacing, number of discontinuity,and the combination of different discontinuous strength on rupture mechanism of the rock mass are analyzed by considering lots of numerical test schemes using the discontinuous deformation analysis method. Finally, considering waterconveyance tunnel in Jurong Pumped Storage Power Station in China as a test case, the tunnel stability under differentdiscontinuities combination is analyzed using discontinuous deformation analysis method. The influence of the optimaltunnel axis and tunnel shape on the stability of surrounding rock is studied by comparative analysis of surrounding rockstability under different tunnel axis and tunnel shapes. The stress concentration in case of the circular tunnel with corneris somehow less than that of the rectangular one.