Using electrical, magnetic and acoustic sensors to detect damage in segmental concrete pipes subjected to permanent ground displacement

This paper describes results of an experimental study that used sensing methods for monitoring damage along segmental concrete pipelines resulting from permanent ground displacement across a simulated earthquake fault. The literature contains examples of such damage occurring during actual earthquakes, significantly impacting the functionality of the pipelines. Detecting the location of the damage and the extent of the damage in pipelines can significantly accelerate post-earthquake repair efforts. In this paper, electrical sensing methods, magnetic sensing, and acoustic emission are used to monitor structural damage in a segmental concrete pipeline during a large-scale test. In this test, the segmental concrete pipeline was subjected to a concentrated transverse permanent ground displacements (PGDs). The majority of the damage to the pipe segments was localized at the joints, especially the bell sections while the damage to the spigots was minimal. The damage extended away from the joints in the pipe segments in the immediate vicinity of the fault line. Telescoping (i.e., crushing of the bell-and-spigot) was a primary mode of failure that was observed. The results of this study indicate that electrical sensing methods (including the use of conductive grout), magnetic sensing, and acoustic emission, employed alone or in combination, can detect and quantify the damage in segmental concrete pipelines.