Technical and Operational Guidelines When Using Strain Gauges to Monitor Pipelines in Slow Moving Landslides

Abstract

Vibrating wire (VW) strain gauges have been used by the pipeline industry for over 50 years as part of landslide hazard management programs. This paper provides technical and operational guidelines for the use of these strain gauges based on 20 years of experience managing active but slow moving landslides. Guidelines are provided for the use of strain gauges during 1) routine monitoring 2) cut outs and 3) strain relief. Examples of expected strain gauge responses are provided along with technical considerations for interpreting data. Given the relatively small size of the gauges in relation to the length of pipeline within most landslides, techniques are provided to best locate the gauges including the use of 1) visual/on-site geotechnical assessments, 2) geotechnical monitoring technologies and 3) smart pigging technologies (caliper, IMU and axial strain technologies). Limitations, reliability, and alternatives to VW gauges are also discussed.