ABSTRACT
An observational approach to tunnel design and construction is commonly employed in order to assess displacements as a result of the excavation process. Temporary tunnel support design decisions are based on such displacement data. In weak ground conditions, a correct and accurate evaluation of such measurements is critical to the safety, sustainability, optimization and to the economics of the construction process. Within this context, the development and application of ground support (i.e. forepoles, spiles, rock bolts etc.) outfitted with fiber optic technology is presented. This state-of-the-art optical technique monitors strain with a spatial resolution of 0.65 mm; allowing a continuous strain profile along the length of the ground support specimen to be determined. It has been shown that this novel technology allows the design engineer to respond and make relevant adjustments to the support regime and excavation process in response to current and potentially future ground conditions.
