This article describes an installation of fiber-optic sensors designed to measure pipe bending due to ground movement at three sites on a 16-inch gas transmission line. The sour gas pipeline had failed in December 2004 from excessive forces related to ground movement. As temporary mitigation, the pipeline was daylighted to reduce the soil traction forces. Before placing the pipeline back into conventional service, however, a comprehensive monitoring program had to be developed, During the time when the section of pipeline was daylighted, three linear and three coiled fiber-optic sensors were installed at each of three sites selected as part of a system designed to measure bending strains as large as 1%. The two types of sensors were placed in pairs approximately at the 12, 4, and 8 o'clock positions.
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