A monitoring program employed to measure the support performance of spiles in a recent Canadian tunnel project is presented. Of novelty in this research is the use of a distributed optical strain sensing technique to measure the load distribution of individual spile support members at a spatial resolution of 0.65mm. The distinct challenges and technique developed to instrument the 6-meter long, self-drilling spile members specified by the design are presented. Additionally, the considerations to effectively monitor the instrumented spiles over a 15-meter section of the tunnel are discussed. Selected load profiles are presented for instrumented spiles over one month of monitoring and approximately 36 meters of tunnel advance. Significant correlations between the measured load of each spile using the optical fiber sensing technology and the qualitative assessments made from within the tunnel were found and highlight the necessity of the support installation regulations implemented at the project.
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