A Fiber Bragg Grating Sensing System and Its Application to Monitoring Landslides and Associated Pipelines

The integrity of oil and gas pipelines is seriously threatened by landslides and other geohazards in tough terrain in western China. Monitoring the landslides with slow, continual movements and the strain build up in pipelines due to landslides is an effective way to maintain the serviceability of pipelines. In this paper, a monitoring system based on Fiber Bragg Grating (FBG) sensors is developed and applied. The system is made up of four related parts: the pipeline strain measurement of the with FBG strain sensors, the soil-pipeline contact pressure detecting with FBG soil pressure cells, the landslide inner deformation monitoring with pipe strain gages and the landslide surface monitoring with a special buried concrete beam with FBG sensors. The system is used to monitor a huge, slow moving landslide and the pipeline affected by it. The monitoring results are analyzed and the pipeline integrity is assessed basing the monitoring results. The FBG system has been proved to be suitable to monitor landslides and pipelines automatically and real-timely.