THE STABILITYOF SHALLOW IN ROCK BASED ON LIMIT ANALYSIS

摘要

Predicting the stability of long rock tunnels presents a significant challenge for geotechnical engineers. This arises due to the difficulty in evaluating the jointed rock mass strength, because rock masses are inhomogeneous, discontinuous media composed of rock material and naturally occurring discontinuities such as joints, fractures and bedding planes. In general, to estimate the stability of rock tunnels, conventional Mohr-Coulomb model using the parameters, c and φ, are used. This study adopts the nonlinear Hoek-Brown failure criterion to deal with the shallow tunnel stability problem. In this paper, numerical finite element upper and lower bound limit analysis has been used conjunction with the latest version of the Hoek-Brown failure criterion. A range of tunnel geometries and material properties are considered and rigorous bounds on the internal tunnel pressure required to prevent collapse are obtained.