A distributed optical fibre monitoring system based on Brillouin Optical Time Domain Reflec-tometry has been used to monitor the strain profile of soil nails installed on a steep highway cut slope along theA2 near Dartford, UK. Soil nails of the required length were assembled in the laboratory and twelve-core ribbonoptical fibre sensor cable was attached using adhesive at frequent intervals along the length. At the site, theinstrumented nails were installed into drilled holes in the cut slope. The holes were then filled with a neat cementgrout. Finally a rock-fall netting was placed over the slope surface and head plates were tightened onto the soilnails. This paper presents a detailed description of the instrumentation, installation and some preliminary resultsof strain profile along the nails. It is expected that the outcome of this research will contribute in upgrading thedesign technique/methodology of soil nails for cut slopes.
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