Tunnelling in Weak Rock

Abstract

The methodology and design procedures for tunnelling within weak rock are nontrivial in nature. Prior to determining the proper tunnelling technique and ground/rock support method, a tunnel design engineer must utilize the data obtained from the site investigation, rock classification and characterization. This chapter summarizes key components associated with weak rock tunnelling. It also includes practical design considerations associated with a Case Study of the Driskos Twin Tunnel as part of the Egnatia Odos Motorway that was constructed in Northern Greece. A section on numerical modelling highlights the challenges and state of the art of such analyses. Finally, a state-of-the-art fiber optic strain sensing technique is included in order to highlight its potential use in future tunnel design, operation and maintenance considerations as warranted by the Observational Method.