Design of tunnels in jointed rock on the basis of mechanical models and classification systems

摘要

The description of the stress-strain behavior and the permeability of a rock mass with the aid of realistic rock mechanical models and corresponding stability analyses have proven to lead to safe and economic design of tunnels in jointed rock. Since several decades classification systems based on rock mass ratings are considered suitable for practical use. Based on thorough investigations, the authors have concluded, that the application of these classification systems involves considerable risks since they reveal substantial shortcomings, which can lead to a noneconomic and even unsafe design.